Producing alpha-olefins using polyketide synthases

ABSTRACT

The present invention provides for a polyketide synthase (PKS) capable of synthesizing an α-olefin, such as 1-hexene or butadiene. The present invention also provides for a host cell comprising the PKS and when cultured produces the α-olefin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 61/387,435, filed Sep. 28, 2010, which is hereby incorporated by reference in its entirety.

STATEMENT OF GOVERNMENTAL SUPPORT

This invention was made with government support under Contract No. DE-AC02-05CH11231 awarded by the U.S. Department of Energy and Award No. 0540879 awarded by the National Science Foundation. The government has certain rights in the invention

FIELD OF THE INVENTION

This invention relates generally to α-olefin production using polyketide synthases and so relates to the fields of chemistry, microbiology, and molecular biology.

BACKGROUND OF THE INVENTION

Type I polyketide synthases (PKSs) are programmable, multifunctional enzymes capable of possessing all of the catalytic capacity of fatty-acid synthases (FASs). However, unlike the FAS enzyme, which iteratively extends and fully reduces the β-carbonyl generated with each extension of the hydrocarbon backbone, PKS systems utilize discrete sets of enzymatic domains for each extension and reduction of the nascent chain. These sets, commonly referred to as modules, can incorporate a variety of extenders units resulting in different side chains. They also can encode between zero and three of the reducing domains associated with FASs, respectively leading to a ketone, hydroxy, double bond, or fully saturated carbon at the beta position of the growing polyketide chain (Hopwood and Sherman. 1990. Annual Review of Genetics 24:37-66).

Due to their modularity, PKS systems have been extensively explored for production of “unnatural” natural products (Weissman and Leadlay. 2005. Nature Reviews Microbiology 3:925-936). Hundreds of these molecules have been produced, ranging from basic lactones to modified versions of drugs and drug-like compounds.

SUMMARY OF THE INVENTION

The present invention provides polyketide synthases (PKSs) capable of synthesizing α-olefins, recombinant expression vectors for producing them, recombinant host cells that express them and produce the desired alpha olefin, methods for making alpha olefins, and alpha olefins produced by the methods. The PKSs of the invention are not naturally occurring and so are referred to as “recombinant” PKS enzymes. In some embodiments of the invention, the α-olefin is not a compound synthesized by a naturally occurring PKS. In some embodiments of the invention, the PKS is a hybrid PKS comprising modules and/or portions thereof, from two, three, four or more naturally occurring PKSs. A hybrid PKS can contain naturally occurring modules from two or more naturally occurring PKSs and/or it can contain one or more modules composed of portions, including intact domains, of two or more modules from the same naturally occurring PKS or from two or more naturally occurring PKS, or both. In some embodiments of the invention, a recombinant nucleic acid comprising a CurM module or portion thereof, which may be either naturally occurring or recombinant, is employed.

The present invention provides recombinant nucleic acids that encode PKSs of the invention. The recombinant nucleic acids include nucleic acids that include a portion or all of a PKS of the invention, nucleic acids that further include regulatory sequences, such as promoter and translation initiation and termination sequences, and can further include sequences that facilitate stable maintenance in a host cell, i.e., sequences that provide the function of an origin of replication or facilitate integration into host cell chromosomal or other DNA by homologous recombination. In some embodiments, the recombinant nucleic acid is stably integrated into a chromosome of a host cell. In some embodiments, the recombinant nucleic acid is a plasmid. Thus, the present invention also provides vectors, including expression vectors, comprising a recombinant nucleic acid of the present invention. The present invention also provides host cells comprising any of the recombinant nucleic acid and/or PKS of the present invention. In some embodiments, the host cell, when cultured under suitable conditions, is capable of producing the α-olefin. These host cells include, for example and without limitation, prokaryotes such as E. coli species, Bacillus species, Streptomyces species, Myxobacterial species, as well as eukaryotes including but not limited to yeast and fungal strains.

Thus, the present invention provides a wide variety of host cell comprising one or more of the recombinant nucleic acids and/or PKSs of the present invention. In some embodiments, the host cell, when cultured, is capable of producing an α-olefin that it otherwise does not produce, or produces at a lower level, in the absence of a nucleic acid of the invention.

The present invention provides methods for producing α-olefins, said methods generally comprising: providing a host cell of the present invention, and culturing said host cell in a suitable culture medium under suitable conditions such that the α-olefin is produced.

The present invention also provides compositions comprising an α-olefin from a host cell in which the α-olefin was produced, and in some embodiments may include trace residues and/or other components of the host cell. Such trace residues and/or other components may include, for example, cellular material produced by the lysis of the host cell. The present invention also provides methods of purifying α-olefins and methods for converting them to other useful products.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and embodiments of the invention as well as others will be readily appreciated by the skilled artisan from the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings.

FIG. 1 shows an illustrative example of the modular organization of a biosynthetic pathway suitable for synthesizing 1-hexene in accordance with the invention. In this illustration, the proposed modules are sourced from the loading module of DEBS1 from the erythromycin PKS, module 5 from the nystatin PKS NysC, and CurM the terminal module of the curacin PKS. In another embodiment of the invention, the nystatin PKS module 5 is replaced with portions of modules 9 and 10 from the indanomycin PKS; this alternative embodiment has actually been used to produce 1-hexene.

FIG. 2 shows types of modules employed and corresponding precursors utilized for incorporation into polyketide chains. The loading module is designated S. While any suitable loading domain can be used (such as those loading acetate and benzoic acid), only two examples are illustrated in this figure. The remaining compounds represent the structures incorporated into the growing polyketide chain employing extender modules A-P. The dashed line indicates the C—C bond formed through Claisen condensation; atoms to the right of the bond and the C atom at the left of the dashed line represent the structures determined by the module employed. The R group represents the existing acyl chain prior to incorporation determined by the module.

FIG. 3 shows: (A) a PKS system that can be used to produce 1-hexene in accordance with the invention, (B) how additional modules can be added to yield longer, even-chain α-olefins, and (C) how changing the loading module to incorporate acetate (from malonyl-CoA) will allow access to the saturated, linear, odd-chain α-olefins in accordance with the methods of the invention.

FIG. 4 shows an embodiment of the invention that illustrates utilization of the avermectin PKS loading module. The side chains illustrated are merely examples and do not constitute the entire pool of side chains that can be incorporated using the avermectin loading module (or similar loading modules) in accordance with the methods and teaching of the invention.

FIG. 5 shows, in part (A), an example of an illustrative pathway to 3-methylenepent-4-enoic acid, an example of the carboxylated butadiene derivatives accessible using PKSs in accordance with the methods of the invention and how the distance between the diene and carboxylate moieties can be increased via the use of additional PKS modules. FIG. 5, part (B), shows the proposed mechanism of the exomethylene biosynthesis from the jamaicamide pathway (see Edwards et al. 2004. Chem. Biol. 11(6):817-33; incorporated herein by reference).

FIG. 6 shows a PKS for producing butadiene in accordance with the methods of the invention. While this invention is not to be limited in any manner by any proposed mechanism of action recited or shown herein, this figure, for simplicity, illustrates loss of the hydroxyl group as a water molecule, the enzymatic mechanism utilizes sulfate as a leaving group.

FIG. 7 shows a PKS for producing butadiene in accordance with the methods of the invention. Parts (A) and (B) show the loading of the acrylyl-CoA using the DEBS propionyl-CoA specific loading domain modified to accept acrylyl-CoA. Part (C) shows the thiotransfer of the acrylate moiety to KS domain. Part (D) shows the binding of the malonyl-CoA and transfer to ACP domain. Part (E) shows KS catalyzing the condensation of the moiety with release of CO₂. Part (F) shows KR catalyzing the reduction of the β-carbonyl group. Part (G) shows the final step and the release of the butadiene, CO₂, and water (as in FIG. 6, the loss of the hydroxyl group is illustrated with a water molecule, but the enzymatic mechanism utilizes sulfate as a leaving group).

FIG. 8 shows an enzymatic pathway accessible by the methods and materials of the invention to produce acrylyl-CoA comprising exogenously supplying propionate, and expressing PrpE and acyl-CoA dehydrogenase activities. A host cell comprising this system would be provided with propionate, which could be exogenously fed to, if not produced endogenously by, the host cell selected for production.

FIG. 9 shows an enzymatic pathway accessible by the methods and materials of the invention to produce acrylyl-CoA comprising exogenously supplying propionate and glucose. A host cell comprising this system would be provided with propionate, either through exogenous feeding or the introduction of propionate biosynthesis pathway, as above, and a suitable organic molecule that the host cell can directly or indirectly convert into a pyruvate. For example, if the host cell is E. coli, the suitable organic molecule can be glucose. This pathway utilizes the central metabolic intermediate pyruvate to produce lactate via a lactate dehydrogenase. Lactate is then converted to lacoyl-CoA by a lactate CoA transferase, utilizing propionyl-CoA as a cofactor and releasing propionate. Lactoyl-CoA is then dehydrated using a lactoyl-CoA dehydratase to yield acrylyl-CoA. One embodiment of this invention includes the lactate dehydrogenase, LdhA, from E. coli, the lactate CoA transferase, Pct, from Clostridium proponicum, and the lactoyl-CoA dehydratase enzymes, EI and EII, from C. proponicum. The introduction of this pathway into E. coli or yeast for diene (such as butadiene) production represents a novel application of these enzymes. An embodiment of this invention is use of this pathway for PKS-based acrylate production.

FIG. 10 shows an enzymatic pathway accessible by the methods and materials of the invention to produce acrylyl-CoA starting from the common metabolic precursor malonyl-CoA. This pathway generates malonyl-CoA using an acetyl-CoA carboxylase, acetyl-CoA and CO₂. Malonyl-CoA is then reduced by a malonyl-CoA reductase releasing malonyl semialdehyde. Malony semialdehyde is converted to 3-hydroxypropionate using a substrate specific oxidoreductase. A 3-hydroxypropionate CoA ligase catalyzes the formation of 3-hydroxypropionyl-CoA. This intermediate is then dehydrated to acryalyl-CoA by the reverse reaction of 3-hydroxypropionyl-CoA hydratase. In one embodiment of the invention, these enzymes are the acetyl-CoA carboxylase complex (AccA/AccD) from E. coli, the malonyl-CoA reductase (The introduction of this pathway into E. coli or yeast for diene (e.g. butadiene) production represents a novel application of these enzymes and is a unique embodiment of this invention. An embodiment of this invention is use of this pathway for PKS-based acrylate production.

FIG. 11 shows an enzymatic pathway accessible by the methods and materials of the invention to produce isoprene via the mevalonate pathway.

FIG. 12 shows an example of an illustrative pathway accessible by a PKS provided by the invention for producing isoprene. (A) shows the loading of the acrylyl-CoA using the DEBS propionyl-CoA specific loading domain modified to accept acrylyl-CoA, and extension with malonyl-CoA to form the beta-keto ACP bound intermediate. Parts (B)-(D) show the HMG-CoA-like mechanism involved in the replacement of the β-carbonyl group with a methyl group using PKS enzymes from the PKSX (Bacillaene) cluster from Bacillus subtilis (Butcher, et al. 2007. Proc Natl Acad Sci USA. 104(5):1506-9; incorporated herein by reference). This invention is not to be limited by any proposed mechanism shown herein. In this embodiment, the penultimate product is released as the free acid and subsequently decarboxylated to isoprene in accordance with the methods of the invention by either a decarboxylase, or extracellular chemical catalysis/pyrolysis.

FIG. 13 shows a PKS provided by the invention for producing (E)-penta-1,3-diene. This figure illustrates loss of the hydroxyl group as a water molecule, but the enzymatic mechanism utilizes sulfate as a leaving group.

FIG. 14 shows precursor supply pathways in E. coli for producing acrylyl-CoA, as described in previous figures, and [2S]-methylmalonyl-CoA. Each enzymes depicted can be expressed in a host cell wherein each enzyme can be independently either endogenous or native to the host cell, or introduced into recombinant

FIG. 15 shows methods and materials provided by the invention for maximizing precursor supply pathways in E. coli. The means to maximizing acrylyl-CoA can comprise one or more of “knocking out” (eliminating or reducing the expression of) PrpC activity, knocking out YgfH activity, exogenously feeding propionate (or producing propionate endogenously), overexpressing PrpE activity to increase cytosolic pools of propionyl-CoA. From this intermediate, the introduction of the propionyl-CoA carboxylase complex (AccA/PccB) will yield methylmalonyl-CoA (Pfeifer, et al. Science. 2001 Mar. 2; 291(5509):1790-2; incorporated herein by reference). This pool of propionyl-CoA can also be utilized in the pathways described in FIGS. 8 and 9.

FIG. 16 shows an illustrative PKS provided by the invention to produce 3-hydroxy-1-octene. The PKS comprises the following elements: (i) Load module and KS1 from PikA1 (pikromycin), followed by (ii) Module 1 and KS2: AT-ACP segment from Module 5 and KS6 domain from the Nystatin PKS, (iii) Module 2: the hydroxymalonate-specific AT and contiguous ACP domains from ZmaA (zwittermicin PKS) from Bacillus cereus, DH, ER and KR domains from nanchangmycin PKS Module 2, and (iv) Module 3: AT-TE segment of the CurM module (curacin PKS). For the production of the precursor hydroxymalonyl-ACP, enzymes ZmaD, ZmaG, and ZmaE are also produced by or provided to the host strain. This figure illustrates loss of the hydroxyl group as a water molecule, however, it should be noted that the enzymatic mechanism utilizes sulfate as a leaving group.

FIG. 17 shows an illustrative PKS provided by the invention to produce 1-decene. The PKS comprises the following elements: (i) Load module and KS 1 from PikA1, followed by (ii) Module 1 and KS2: AT-ACP segment from Module 5 and KS6 domain from the nystatin PKS, (iii) Module 2 and KS3: AT-ACP segment from Module 15 and KS 16 domain from the nystatin PKS, (iv) Module 3 and KS4: AT-ACP segment from Module 3 and K4 domain from the oligomycin PKS, and (v) Module 4: AT-TE segment from CurM. This figure illustrates loss of the hydroxyl group as a water molecule, however, it should be noted that the enzymatic mechanism utilizes sulfate as a leaving group.

FIG. 18 shows an illustrative PKS provided by the invention to produce 1-octene. The PKS comprises the following elements: (i) Loading Module and KS1 from PikA1, followed by (ii) Module 1 and KS2: AT-ACP segment from Module 5 and KS6 domain from the nystatin PKS Module 2, (iii) and KS3: AT-ACP segment from Module 15 and KS16 domain from the nystatin PKS, and then (iv) Module 3: AT-ST segment from the CurM module. This figure illustrates loss of the hydroxyl group as a water molecule, however, it should be noted that the enzymatic mechanism utilizes sulfate as a leaving group.

DETAILED DESCRIPTION

This invention is not limited to particular embodiments described, as such may, of course, vary. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, because the scope of the present invention will be limited only by the appended claims.

Where a range of values is provided, each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the invention.

Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in practicing the present invention, suitable methods and materials are now described. All publications cited are incorporated herein by reference to disclose and describe the methods and/or materials and/or results therein.

As used herein and in the appended claims, the singular forms “a”, “and”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an α-olefin” includes a plurality of such α-olefins, and so forth.

The term “even-chain α-olefin” refers to an α-olefin with a carbon backbone, which, disregarding any functional groups or substituents, has an even number of carbon atoms.

The term “odd-chain α-olefin” refers to an α-olefin with a carbon backbone, which, disregarding any functional groups or substituents, has an odd number of carbon atoms.

The term “functional variant” describes an enzyme that has a polypeptide sequence that is at least 70%, 75%, 80%, 85%, 90%, 95% or 99% identical to an enzyme described herein. A “functional variant” enzyme may retain amino acids residues recognized as conserved for the enzyme in nature, and/or may have non-conserved amino acid residues. Amino acids can be, relative to the native enzyme, substituted (different), inserted, or deleted, but the variant has generally similar enzymatic activity as compared to an enzyme described herein. A “functional variant” enzyme may be found in nature or be an engineered mutant (recombinant) thereof.

The objects, advantages, and features of the invention will become more apparent to those persons skilled in the art upon reading the details of the invention as more fully described below.

Polyketide Synthases (PKS)

The present invention provides recombinant polyketide synthase (PKS) enzymes capable of synthesizing an α-olefin. The PKS enzymes of the invention are not naturally occurring PKS. In some embodiments of the invention, the α-olefin is not a compound synthesized by a naturally occurring PKS. In some embodiments of the invention, the PKS is a hybrid PKS comprising modules, domains, and/or portions thereof, or functional variants thereof, from two or more PKSs. Such α-olefins include the diketides and triketides, and polyketides of more than three ketide units, such as 4, 5, or 6 or more ketide units. The α-olefin can further include one or more functional groups in additional to the double bond that characterizes them. Such functional groups include, but are not limited to, ethyl, methyl and hydroxy side chains, internal olefins, and ketones.

In some embodiments of the invention, the α-olefin is an even-chain α-olefin having the following chemical structure:

wherein each R₁ is independently —H or —CH₃, each R₂ is independently —H or —OH, n is an integer, and αβ is a single or double bond, with the proviso that when an αβ is a double bond then the corresponding R₂ is H. In some embodiments of the invention, n is an integer from 1 to 10. n indicates the number of two-carbon-chain subunits in the carbon backbone of the α-olefin. The R₁, R₂, and αβ within each two-carbon-subunit of a multiple subunit α-olefin is independent of the R₁, R₂, and αβ of any other two-carbon-subunit in the molecule. In some embodiments, however, one or more, up to all, subunits have identical R₁, R₂, and αβ.

In some embodiments of the invention, the α-olefin has the following chemical structure:

wherein n is an integer from 0 to 10.

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C3-alpha olefins propylene (propene) and polymers and products derived therefrom, including but not limited to: polypropylene, acylonitrile, propylene oxide, alcohols, cumene, acrylic acid, injection molded plastics, electronics, electrical appliances, housewares, bottle caps, toys, luggage, films, fibers, carpets, clothing, ropes, pipes, conduit, wire, cable, elastomeric polymers, acrylic fibers, nitrile rubber, acrylonitrile-butadiene-styrene (ABS) resins, styrene-acrylonitrile (SAN) resins, acrylamide, adiponitrile, polyether polyols, polyurethanes, flexible foams, rigid foams, insulation, propylene glycol, polyester resins, antifreeze, de-icing fluids, propylene glycol ethers, paints, coatings, inks, resins, cleaners, isopropanol, cosmetics, pharmaceuticals, food, ink, adhesives, 2-ethylhexanol, phthalate plasticizers, phenol, acetone, polycarbonate, phenolic resins, epoxy resins, methyl methacrylate (MMA), and acrylic esters.

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C4-alpha olefin butene and polymers and products derived therefrom, including but not limited to: polybutylene, copolymers with ethylene and/or propene, hot-melt adhesives, synthetic rubber, diesel fuel, and jet fuel.

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C4 diolefin butadiene and polymers and products derived therefrom, including but not limited to: styrene butadiene rubber (SBR), polybutadiene rubber, acrylonitrile butadiene styrene (ABS), styrene butadiene (SB) copolymer latex, nitrile rubber, adiponitrile, chloroprene, butanediol, tetrahydrofuran, tires, adhesives; coatings, high impact polystyrene, thermoplastic resins, engineering nylons (from C12 lactam), paper coating, gaskets and seals, hoses, gloves, nylon fibers, polymers, wet suits, electrical insulation, polybutylene terephthalate, spandex, and binders. Butadiene has the following chemical structure:

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C5 α olefin: 1-pentene and polymers and products derived therefrom, including but not limited to: gasoline, polymers; adhesives, sealants, diesel fuel, and jet fuel.

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C6 α-olefin (see FIG. 1, example): 1-hexene and polymers and products derived therefrom, including but not limited to comonomer, polyethylene, polymer, high density polyethylene (IIDPE), linear low density polyethene (LLDPE), 1-heptanal, heptanoic acid, resin, film, plastic pipe, containers, diesel fuel, and jet fuel. 1-hexene has the following chemical structure:

and an illustration of a 1-hexene producing PKS is provided in FIG. 1.

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C10 α-olefin: 1-decene and polymers and products derived therefrom, including but not limited to: detergent formulations, linear alkyl benzene (LAB), linear alkyl benzene sulfonate (LABS), polyalphaolefin synthetic lubricant basestocks (PAO), heatshrink materials, electrical insulation sleeves, rash guards in clothing, polyolefin elastomers (POE), flexible foams, footwear, seat cushions, armrests, pillows, radar coolants, strings, polyol esters, detergent alcohols, plasticizer alcohols, specialty chemicals, epoxides, derivatives thereof, comonomer, intermediate in production of epoxides, amines, oxo alcohols, synthetic lubricants, synthetic fatty acids, alkylated aromatics, emulsifiers, performance waxes, cosmetic formulations, viscosity controller, solvent, decene butene copolymer, binder, film forming, decene/PVP copolymer, food additives, glazing agent, anti-foaming agent, anti-dusting agent, white mineral oil substitute, polishing agent, well fluids, alpha olefin oligomers, and the like. 1-decene has the following chemical structure:

In one embodiment, the invention provides methods, host cells, and nucleic acids for making the C8 aromatic α-olefin: styrene and polymers and products derived therefrom, including but not limited to: homopolymers, copolymers, polystyrene, expandable polystyrene (EPS), acrylonitrile-butadiene-styrene (ABS), resins, styrene-acrylonitrile (SAN), acrylonitrile-styrene-acrylate (ASA), styrene butadiene, styrene butadiene rubber, copolymer with maleic anhydride, terephthalate, unsaturated polyester resins, containers, closures, lids and vending cups, construction; electrical and electronic parts; domestic appliances and housings; household goods and home furnishings; and toys, sporting goods and recreational articles, packaging, thermoplastics, cutlery, CDs, insulating materials, polymer bonded explosives, consumer products, renewable plastics, renewable products, hardhats, tires, etc. In some embodiments of the invention, the aromatic α-olefin has the following chemical structure:

wherein R₃ is —H, —OH, —NH₃, or —NO₂.

Alpha olefins are commonly used in the cosmetics and skin care industry, and the present invention therefore provides useful starting materials for making cosmetics and skin care products. For example, alpha olefin sulfonate, sulfate free personal cleaners, soap, copolymer maleic acid, and the like are all used in these industries and provided by the invention. Alpha olefins provide by the invention can also be used in the flavor and fragrance industry. For example, 3-hydroxy-1-octene and 3-oxo-1-octene can be made using the methods and materials of the invention and are used in applications where a mushroom flavor/fragrance is desired.

The present invention can also be used to generate intermediates useful in the synthesis of pharmaceuticals. These olefins can be coupled via olefin metathesis to one another or other olefin intermediates obtained via traditional chemical syntheses to yield bioactive molecules useful as drugs.

In some embodiments, the α-olefin produced in accordance with the invention is (E)-deca-1,5-diene, which has the following chemical structure:

In some embodiments, the α-olefin produced in accordance, with the invention has the following chemical structure:

wherein R is one of the following structures:

In some embodiments, the α-olefin produced in accordance with the invention is a polyolefin having chemical structure (I) and comprising at least two, three, four, five, or more C—C double bonds. Such α-olefins include, but are not limited to, diolefins, such as diolefins with two C—C double bonds on the carbon backbone. Such diolefins include, but are not limited to, butadiene, isoprene, and penta-1,3-diene. Butadiene has the chemical structure shown in [0043], above.

In some embodiments, the α-olefin produced in accordance with the invention is isoprene, which has the following chemical structure:

In some embodiments, the α-olefin produced in accordance with the invention is penta-1,3-diene, which has the following chemical structure:

Complex polyketides comprise a large class of natural products that are synthesized in bacteria (mainly members of the actinomycete family; e.g. Streptomyces), fungi and plants. Polyketides form the macrolactone component of a large number of clinically important drugs, such as antibiotics (e.g. erythromycin, tylosin), antifungal agents (e.g. nystatin), anticancer agents (e.g. epothilone), immunosuppressives (e.g. rapamycin), etc. Though these compounds do not resemble each other either in their structure or their mode of action, they share a common basis for their biosynthesis, which is carried out by a group of enzymes designated polyketide synthases.

Polyketide synthases (PKS) employ short chain fatty acyl CoAs in Claisen condensation reactions to produce polyketides. Unlike fatty acid synthases that utilize acetyl CoA as the starter and malonyl CoA as the extender units, and use a single module iteratively to produce the nascent acyl chains, PKSs are composed of discrete modules, each catalyzing the chain growth of a single step. Modules can differ from each other in composition, so that, overall, a number of different starters (e.g. acetyl CoA, propionyl CoA) and extenders, some of which contain stereospecific methyl (or ethyl) side chains can be incorporated into a polyketide. In addition, PKS modules do not always reduce the 3-carbonyl formed from condensation but may leave it either unreduced (ketone), partially reduced (hydroxyl, 2,3-ene), or fully reduced (3-methylene). Many PKSs employ malonyl CoA or [S]-2-methylmalonyl CoA as the starter for polyketide synthesis. In such cases, the terminal carboxyl group is usually removed by a decarboxylase domain present at the N-terminus of the loading domain of the PKS. Thus, the structure (and chirality) of the α-carbon and β-carbonyl is determined by the module of the PKS employed in the synthesis of the growing chain at each particular step. Because of the correspondence between the modules used in the synthesis and the structure of the polyketide produced, it is possible to program PKS synthesis to produce a compound of desired structure by selection and genetic manipulation of polyketide synthases.

FIG. 2 shows the various modules and the precursor utilized by each module for incorporation into the corresponding nascent acyl (polyketide) chain to give rise to a range of compounds of interest. Table 1, below, provides illustrative PKS sources for each module in FIG. 2. Each PKS source (amino acid sequence and corresponding coding sequence) is well-known to one skilled in the art and readily available. In addition, for each module in Table 1, there are other modules from other PKS (or from recombinant DNA technology) that can be used. In addition, other structures can be incorporated in the ketide or polyketide that are not shown in Table 1 and FIG. 2. For example, useful loading modules includes the benzoate loading module of soraphen PKS, the isobutyrate loading module of the lipomycin PKS and bafilomycin PKS, and the acrylate loading module from the dificidin pathway. The acrylate loading module from the dificidin PKS loads and dehydrates a hydroxypropionate molecule by the use of enzymes difA-E to yield a PKS with an arylyl-ACP (Chen, 2006, J. Bact. 188:4024-4036; incorporated herein by reference).

The present invention also contemplates the use of functional variants of PKS modules, domains, and portions thereof. In one important embodiment, the invention provides a variety of recombinant modules that carry out the same enzymatic reactions conducted by the CurM module.

TABLE 1 PKS sources of the various modules. Module PKS Source S1 Spiramycin PKS Loading Domain (with and without inactivation or deletion of the KS^(Q) domain) S2 Pikromycin PKS Loading Domain (with and without inactivation or deletion of the KS^(Q) domain) S3 Spiramycin PKS Loading Domain S4 Erythromycin PKS Loading Domain A Rifamycin PKS Module 2 B Oligomycin PKS Module 1 C Spiramycin PKS Module 1 D Pikromycin PKS Module 2 E Oligomycin PKS Module 3 F Erythromycin PKS Module 3 G Oligomycin PKS Module 5 H Primaricin PKS Module 7 I Tylosin PKS Module 1 J Erythromycin PKS Module 1 K Avermectin PKS Module 7 L Rapamycin PKS Module 1 M Erythromycin PKS Module 4 N Pederin Module 2 O Ascomycin Module 4 P FK506 Module 4 Q Curacin A Chain Termination Module (CurM)

All extender modules carry the β-acyl ACP synthase (commonly called the ketosynthase or KS) domain, which conducts the decarboxylative condensation step between the extender and the growing polyketide chain, and the acyl carrier protein (ACP) domain that carries the growing acyl chain and presents it to any cognate reductive domains for reduction of the β-carbonyl. Modules can differ from each other in composition so that a number of different starter and extender units, some of which contain stereospecific side chains (e.g. methyl, ethyl, propylene) can be incorporated. The acyltransferase (AT) domain of each module determines the extender unit (e.g. malonyl CoA, methylmalonyl CoA, and the like) incorporated. In addition, PKS modules do not always reduce the (3-carbonyl formed from condensation but may leave it either unreduced (ketone), partially reduced (hydroxyl, 2,3-ene) or fully reduced (3-methylene), as shown in FIG. 2. The ketoreductase (KR) domain reduces the ketone to the OH function (stereospecifically); the dehydratase (DH) domain removes water from the α and β carbons leaving an α,β trans-double bond; the enoylreductase (ER) domain reduces the double bond to a β-methylene center; the reductive state of the β-carbonyl, therefore, is determined by the presence of functional reductive domains in the corresponding module. Less commonly, modules may contain an additional C-methylation domain (yielding an additional α-methyl side chain, as in epothilone).

The Curacin A Chain Termination Module is annotated as CurM. CurM catalyzes an extension of the nascent polyketide molecule with acetate (from malonyl-CoA). The resulting beta carbonyl is reduced to a hydroxyl group by a KR domain. The resulting beta hydroxyl group is then sulfonated by the ST domain (from the common metabolic precursor 3′-phosphoadenosine-5′-phosphosulfate). The TE domain releases the 3-sulfo polyketide which then undergoes loss of sulfate and a decarboxylation to form a terminal olefin moiety. The chain termination module of the PKS of the present invention can comprise the ST and TE domains of the CurM Chain Termination Module and variants thereof with similar activity. Additional PKS modules carrying the combination of a sulfotransferase (pfam00685)/thioesterase have been identified in nature and can be used in additional embodiments of the invention. One such olefination module (Ols) has been characterized from Synechococcus sp. strain PCC 7002 (Mendez-Perez et al. 2011. Appl. Env. Microbiol. 77:4264-4267 2011). Others include, but are not limited to, PKS enzymes from Cyanothece sp. PCC 7424, Cyanothece sp. PCC 7822, Prochloron didemni P1-Palau, Pseudomonas entomophila L48, and Haliangium ochraceum DSM 14365. The present invention also provides consensus sequences that differ from these naturally occurring sequences but encode similar enzymatic activities.

The makeup of the PKS, therefore, determines the choice of starter and extender acyl units incorporated, the extent of reduction at each condensation step, and the total number of units added to the chain. The wide diversity of structures of polyketides seen in nature is thus attributable to the diversity in PKS enzymes.

A partial list of PKS amino acid and corresponding nucleic acid coding sequences that can be used in the PKSs of the present invention includes, for illustration and not limitation, Ambruticin (U.S. Pat. No. 7,332,576); Avermectin (U.S. Pat. No. 5,252,474; MacNeil et al., 1993, Industrial Microorganisms: Basic and Applied Molecular Genetics, Baltz, Hegeman, & Skatrud, eds. (ASM), pp. 245-256; MacNeil et al., 1992, Gene 115: 119-25); Candicidin (FRO008) (Hu et al., 1994, Mol. Microbiol. 14: 163-72); Curacin A (Chang et al., 2004, J. Nat. Prod., 67 (8), pp 1356-1367; Gu et al., 2009, J. Am. Chem. Soc., 131 (44), pp 16033-16035); Epothilone (U.S. Pat. No. 6,303,342); Erythromycin (WO 93/13663; U.S. Pat. No. 5,824,513; Donadio et al., 1991, Science 252:675-79; Cortes et al., 1990, Nature 348:176-8); FK506 (Motamedi et al., 1998, Eur. J. Biochem. 256:528-34; Motamedi et al., 1997, Eur. J. Biochem. 244:74-80); FK520 or ascomycin (U.S. Pat. No. 6,503,737; see also Nielsen et al., 1991, Biochem. 30:5789-96); Jerangolid (U.S. Pat. No. 7,285,405); Leptomycin (U.S. Pat. No. 7,288,396); Lovastatin (U.S. Pat. No. 5,744,350); Nemadectin (MacNeil et al., 1993, supra); Niddamycin (Kakavas et al., 1997, J. Bacteriol. 179:7515-22); Oleandomycin (Swan et al., 1994, Mol. Gen. Genet. 242:358-62; U.S. Pat. No. 6,388,099; Olano et al., 1998, Mol. Gen. Genet. 259:299-308); Pederin (PCT publication no. WO 2003/044186); Pikromycin (Xue et al., 2000, Gene 245:203-211); Pimaricin (PCT publication no. WO 2000/077222); Platenolide (EP Pat. App. 791,656); Rapamycin (Schwecke et al., 1995, Proc. Natl. Acad. Sci. USA 92:7839-43); Aparicio et al., 1996, Gene 169:9-16); Rifamycin (August et al., 1998, Chemistry & Biology, 5: 69-79); Soraphen (U.S. Pat. No. 5,716,849; Schupp et al., 1995, J. Bacteriology 177: 3673-79); Spiramycin (U.S. Pat. No. 5,098,837); and Tylosin (EP 0 791,655; Kuhstoss et al., 1996, Gene 183:231-36; U.S. Pat. No. 5,876,991); each of the foregoing references is incorporated herein by reference. Additional suitable PKS coding are readily available to one skilled in the art (e.g., by cloning and sequencing of DNA from polyketide producing organisms or by reference to GenBank).

Of the more than one hundred PKSs studies and reported on in the scientific literature, the correspondence between the modules used in the biosynthesis of, and the structure of, the polyketide produced is understood both at the level of the protein sequence of the PKS and the DNA sequence of the corresponding genes. The organization of modules and correspondence with polyketide structure can be identified by amino acid and/or nucleic acid sequence determination. One can thus clone (or synthesize) DNA sequences corresponding to desired modules and transfer them as fully functioning units to heterologous hosts, including otherwise non-polyketide producing hosts such as E. coli (Pfeifer, et al., Science 291, 1790 (2001); incorporated herein by reference), and polyketide-producing hosts, such as Streptomyces (Kao et al., Science 265, 509 (1994); incorporated herein by reference).

Additional genes employed in polyketide biosynthesis have also been identified. Genes that determine phosphopantetheine:protein transferase (PPTase) that transfer the 4-phosphopantetheine co-factor of the ACP domains, commonly present in polyketide producing hosts, have been cloned in E. coli and other hosts (Weissman et al., Chembiochem 5, 116 (2004); incorporated herein by reference). While it is possible to re-program polyketide biosynthesis to produce a compound of desired structure by either genetic manipulation of a single PKS or by construction of a hybrid PKS composed of modules from two or more sources (see Weissman et al., supra), the present invention provides the first means for making an alpha-olefin by a recombinant PKS.

Recombinant methods for manipulating modular PKS genes to make the PKSs of the present invention are described in U.S. Pat. Nos. 5,672,491; 5,843,718; 5,830,750; 5,712,146; and 6,303,342; and in PCT publication nos. WO 98/49315 and WO 97/02358; each of which is incorporated herein by reference. A number of genetic engineering strategies have been used with various PKSs to demonstrate that the structures of polyketides can be manipulated to produce novel polyketides (see the patent publications referenced supra and Hutchinson, 1998, Curr. Opin. Microbiol. 1:319-329, and Baltz, 1998, Trends Microbiol. 6:76-83; incorporated herein by reference). In some embodiments, the components of the hybrid PKS are arranged onto polypeptides having interpolypeptide linkers that direct the assembly of the polypeptides into the functional PKS protein, such that it is not required that the PKS have the same arrangement of modules in the polypeptides as observed in natural PKSs. Suitable interpolypeptide linkers to join polypeptides and intrapolypeptide linkers to join modules within a polypeptide are described in PCT publication No. WO 00/47724, incorporated herein by reference.

The vast number of polyketide pathways that have been elucidated to date and the present invention in combination provide a variety of different options to produce α-olefins in accordance with the invention. While the products can be vastly different in size and functionality, all employ similar methods for preparing the PKS and corresponding coding sequence and for producing the desired α-olefin. The interfaces between non-cognate enzyme partners can be optimized on a case-by-case basis. ACP-linker-KS and ACP-linker-TE regions from the proteins of interest will be aligned to examine the least disruptive fusion point for the hybrid synthase. Genetic constructions will employ sequence and ligation independent cloning (SLIC), or other sequence independent cloning techniques, so as to eliminate the incorporation of genetic “scarring”.

In some embodiments, the PKS that produces the α-olefin of interest comprises the sulfotransferase (ST)-thioesterase (TE) domains from Lyngbya majuscula CurM or similar domains from another naturally occurring PKS or one of the recombinant domains provided by the invention. The α-olefins capable of being produced by the invention include, but are not limited to, the diketides propylene, 1-butene, and styrene and the triketides 1-hexene and 1-pentene. In one aspect of the invention, the host cell is fed or exogenously provided or endogenously produces acrylate and so produces diolefins such as 1,5-hexadiene and butadiene. In another aspect, feeding or exogenously providing or endogenous production of benzoic acid to the host cell comprising a PKS of the invention enables the production of styrene derivatives.

In some embodiments, host cells that are capable of producing diolefins are also capable of producing acrylate or acrylyl-CoA/ACP, thus eliminating the need for exogenous acrylate. By coupling one of many PKS thioesterase domains to the module loading acrylate from these precursor pathways, the PKS system is capable of producing acrylic acid. Acrylic acid can also be obtained from acrylyl-CoA or acrylyl-ACP by use of a non-PKS hydrolase in accordance with the invention. In some embodiments of the invention, host cells that are capable of producing diolefins are also capable of producing benzoate.

L. majuscula CurM ST-TE domains comprise the following amino acid sequence:

(SEQ ID NO: 10) F ILSSPRSGST LLRVMLAGHS SLFSPPELHL LPFNTMKERQ EQLNLSYLGE GLQKTFMEVK NLDATASQAL IKDLESQNLS IQQVYGMLQE NIAPRLLVDK SPTYAMEPTI LERGEALFAN SKYIYLVRHP YSVIESFVRM RMQKLVGLGE ENPYRVAEQV WAKSNQNILN FLSQLEPERQ HQIRYEDLVK KPQQVLSQLC DFLNVPFEPE LLQPYQGDRM TGGVHQKSLS ISDPNFLKHN TIDESLADKW KTIQLPYPLK SETQRIASQL SYELPNLVTT PTNQQPQVST TPSTEQPIME EKFLEFGGNQ ICLCSWGSPE HPVVLCIHGI LEQGLAWQEV ALPLAAQGYR VVAPDLFGHG RSSHLEMVTS YSSLTFLAQI DRVIQELPDQ PLLLVGHSMG AMLATAIASV RPKKIKELIL VELPLPAEES KKESAVNQLT TCLDYLSSTP QHPIFPDVAT AASRLRQAIP SLSEEFSYIL AQRITQPNQG GVRWSWDAII RTRSILGLNN LPGGRSQYLE MLKSIQVPTT LVYGDSSKLN RPEDLQQQKM TMTQAKRVFL SGGHNLHIDA AAALASLILT S

L. majuscula CurM ST domain comprises the following amino acid sequence:

(SEQ ID NO: 11) F ILSSPRSGST LLRVMLAGHS SLFSPPELHL LPFNTMKERQ EQLNLSYLGE GLQKTFMEVK NLDATASQAL IKDLESQNLS IQQVYGMLQE NIAPRLLVDK SPTYAMEPTI LERGEALFAN SKYIYLVRHP YSVIESFVRM RMQKLVGLGE ENPYRVAEQV WAKSNQNILN FLSQLEPERQ HQIRYEDLVK KPQQVLSQLC DFLNVPFEPE LLQPYQGDRM TGGVHQKSLS ISDPNFLKHN TIDESLADKW KTIQLPYPLK

L. majuscula CurM TE domain comprise the following amino acid sequence:

(SEQ ID NO: 12) EKFLEFGGNQ ICLCSWGSPE HPVVLCIHGI LEQGLAWQEV  ALPLAAQGYR VVAPDLFGHG RSSHLEMVTS YSSLTFLAQI DRVIQELPDQ PLLLVGHSMG AMLATAIASV RPKKIKELIL VELPLPAEES KKESAVNQLT TCLDYLSSTP QHPIFPDVAT AASRLRQAIP SLSEEFSYIL AQRITQPNQG GVRWSWDAII RTRSILGLNN LPGGRSQYLE MLKSIQVPTT LVYGDSSKLN  RPEDLQQQKM TMTQAKRVFL SGGHNLHIDA AAALASLILT  S

In some embodiments, the PKS of the present invention comprises a naturally occurring sulfotransferase-thioesterase (ST-TE) domains, or ST or TE domain, functionally similar, but not identical, to L. majuscula CurM. In some embodiments, the PKS of the present invention comprises the amino acid sequences of the ST and/or TE of any of the proteins/peptides described in Tables 2-4, or functionally variants thereof. One skilled in the art can identify such L. majuscula CurM-like ST and/or TE domains using available bioinformatics programs. For example, the L. majuscula CurM ST-TE can be split in two separately functional portions by relying on its crystal structure and annotation of catalytic boundaries with programs like protein BLAST, and the sequences can be homology-modeled to get a better grasp of the boundary of catalytic domains, using L. majuscula CurM ST-TE as an anchoring template. Together, such methods can be employed to make solid predictions about catalytic activity and responsible amino acid regions within a larger protein.

In some embodiments, ST and/or TE domains, or functionally variants thereof, comprise one or more of the following amino acid residues (using L. majuscula CurM as a reference sequence): R205, H266, S100, E124, N211, and N267. In some embodiments, ST and/or TE domains, or functionally variants thereof, comprise the following amino acid residues (using L. majuscula CurM as a reference sequence): 8205 and H266, and optionally one or more of S100, E124, N211, and N267. In some embodiments, the PKS comprises a ST domain and a TE domains that are derived or obtained from two different organisms or sources.

TABLE 2 List of proteins/peptides comprising CurM-like ST-TE domains. Ref. Protein/peptide No. of amino acid [organism or source] residues Accession No. 1. polyketide synthase module 2211 aa protein ZP_08432359.1 GI:332712433 [Lyngbya majuscula 3L] 2. CurM [Lyngbya majuscula] 2147 aa protein AAT70108.1 GI:50082961 3. beta-ketoacyl synthase 2762 aa protein YP_002377174.1 GI:218438845 [Cyanothece sp. PCC 7424] 4. beta-ketoacyl synthase 2775 aa protein YP_003887107.1 GI:307151723 [Cyanothece sp. PCC 7822] 5. polyketide synthase 2999 aa protein AEH57210.1 GI:335387269 [Prochloron didemni P1-Palau] 6. Chain A, Thioesterase Domain 286 aa protein 3QIT_A GI:325534050 From Curacin Biosynthetic Pathway 7. polyketide synthase module 2277 aa protein ZP_08425908.1 GI:332705832 [Lyngbya majuscula 3L] 8. polyketide synthase 2720 aa protein YP_001734428.1 GI:170077790 [Synechococcus sp. PCC 7002] 9. polyketide synthase 1217 aa protein YP_610919.1 GI:104784421 [Pseudomonas entomophila L48] 10. KR domain-containing protein 3045 aa protein YP_003265308.1 GI:262194099 [Haliangium ochraceum DSM 14365] 11. OciA 2858 aa protein ABW84363.1 GI:158954787 [Planktothrix agardhii NIES-205] 12. OciA 3477 aa protein ABI26077.1 GI:112824006 [Planktothrix agardhii NIVA-CYA 116] 13. CurM 358 aa protein YP_001062692.1 GI:126444569 [Burkholderia pseudomallei 668] 14. amino acid adenylation domain-containing 1470 aa protein YP_003137597.1 GI:257059709 protein [Cyanothece sp. PCC 8802] 15. amino acid adenylation domain-containing 1470 aa protein YP_002372038.1 GI:218246667 protein [Cyanothece sp. PCC 8801] 16. polyketide synthase 18193 aa protein XP_001416378.1 GI:145343541 [Ostreococcus lucimarinus CCE9901]

TABLE 3 List of proteins/peptides comprising a CurM-like ST domain. Ref. Protein/peptide No. of amino acid [organism or source] residues Accession No. 1. polyketide synthase module 2211 aa protein ZP_08432359.1 GI:332712433 [Lyngbya majuscula 3L] 2. CurM 2147 aa protein AAT70108.1 GI:50082961 [Lyngbya majuscula] 3. beta-ketoacyl synthase 2762 aa protein YP_002377174.1 GI:218438845 [Cyanothece sp. PCC 7424] 4. beta-ketoacyl synthase 2775 aa protein YP_003887107.1 GI:307151723 [Cyanothece sp. PCC 7822] 5. polyketide synthase 2999 aa protein AEH57210.1 GI:335387269 [Prochloron didemni P1-Palau] 6. polyketide synthase module 2277 aa protein ZP_08425908.1 GI:332705832 [Lyngbya majuscula 3L] 7. polyketide synthase 2720 aa protein YP_001734428.1 GI:170077790 [Synechococcus sp. PCC 7002] 8. polyketide synthase 1217 aa protein YP_610919.1 GI:104784421 [Pseudomonas entomophila L48] 9. OciA 2858 aa protein ABW84363.1 GI:158954787 [Planktothrix agardhii NIES-205] 10. OciA 3477 aa protein ABI26077.1 GI:112824006 [Planktothrix agardhii NIVA-CYA 116] 11. CurM 358 aa protein YP_001062692.1 GI:126444569 [Burkholderia pseudomallei 668] 12. KR domain-containing protein 3045 aa protein YP_003265308.1 GI:262194099 [Haliangium ochraceum DSM 14365] 16. COG3321: Polyketide synthase modules and 11541 aa protein XP_003074830.1 GI:308800098 related proteins (ISS) [Ostreococcus tauri] 17. polyketide synthase 18193 aa protein XP_001416378.1 GI:145343541 [Ostreococcus lucimarinus CCE9901] 18. modular polyketide synthase type I 14149 aa protein XP_002507643.1 GI:255071123 [Micromonas sp. RCC299] 19. hypothetical protein RBXJA2T_11932 301 aa protein ZP_08402700.1 GI:332526592 [Rubrivivax benzoatilyticus JA2] 20. hypothetical protein Dshi_1965 310 aa protein YP_001533306.1 GI:159044512 [Dinoroseobacter shibae DFL 12] 21. hypothetical protein glr1901 301 aa protein NP_924847.1 GI:37521470 [Gloeobacter violaceus PCC 7421] 22. hypothetical protein Sros_9233 290 aa protein YP_003344594.1 GI:271970398 [Streptosporangium roseum DSM 43021] 23. hypothetical protein SAV_2309 299 aa protein NP_823485.1 GI:29828851 [Streptomyces avermitilis MA-4680] 24. conserved hypothetical protein 289 aa protein ZP_07307763.1 GI:302555421 [Streptomyces viridochromogenes DSM 40736] 25. sulfotransferase 332 aa protein YP_004017900.1 GI:312197839 [Frankia sp. EuI1c] 26. hypothetical protein Nit79A3_2110 304 aa protein YP_004695298.1 GI:339483512 [Nitrosomonas sp. Is79A3] 27. sulfotransferase 346 aa protein YP_003651260.1 GI:296268628 [Thermobispora bispora DSM 43833] 28. sulfotransferase 264 aa protein YP_004017815.1 GI:312197754 [Frankia sp. EuI1c] 29. hypothetical protein gll1899 320 aa protein NP_924845.1 GI:37521468 [Gloeobacter violaceus PCC 7421] 30. SecC motif-containing protein 359 aa protein YP_001093305.1 GI:127512108 [Shewanella loihica PV-4] 31. predicted protein 507 aa protein XP_003055946.1 GI:303273170 [Micromonas pusilla CCMP1545] 32. Putative protein-tyrosine sulfotransferase 305 aa protein ZP_01905212.1 GI:149916710 [Plesiocystis pacifica SIR-1] 33. hypothetical protein PB2503_07444 310 aa protein YP_003854688.1 GI:304321045 [Parvularcula bermudensis HTCC2503] 34. hypothetical protein PPE_01162 422 aa protein YP_003869548.1 GI:308067943 [Paenibacillus polymyxa E681] 35. putative sulfotransferase 339 aa protein YP_001822417.1 GI:182434698 [Streptomyces griseus subsp. griseus NBRC 13350] 36. hypothetical protein LYNGBM3L_54590 318 aa protein ZP_08430625.1 GI:332710682 [Lyngbya majuscula 3L] 37. SecC motif-containing protein 336 aa protein YP_001473003.1 GI:157374403 [Shewanella sediminis HAW-EB3] 38. sulfotransferase domain protein 329 aa protein ZP_01905835.1 GI:149917336 [Plesiocystis pacifica SIR-1] 39. sulfotransferase [Streptomyces cf. griseus XylebKG-1] 339 aa protein ZP_08234477.1 GI:326775212 40. hypothetical protein Sros_1208 347 aa protein YP_003336949.1 GI:271962753 [Streptosporangium roseum DSM 43021] 41. sulfotransferase 430 aa protein YP_722743.1 GI:113476682 [Trichodesmium erythraeum IMS101] 42. hypothetical protein Sros_1207 336 aa protein YP_003336948.1 GI:271962752 [Streptosporangium roseum DSM 43021] 43. sulfotransferase 322 aa protein YP_004602630.1 GI:336322663 [Flexistipes sinusarabici DSM 4947] 44. Protein-tyrosine sulfotransferase 381 aa protein EFN77815.1 GI:307196126 [Harpegnathos saltator] 45. sulfotransferase domain protein 346 aa protein ZP_05076043.1 GI:254462627 [Rhodobacterales bacterium HTCC2083] 46. PREDICTED: similar to Transport and 382 aa protein XP_968004.1 GI:91090216 Golgi organization 13 CG32632-PB [Tribolium castaneum] 47. sulfotransferase 335 aa protein YP_943667.1 GI:119945987 [Psychromonas ingrahamii 37] 48. hypothetical protein sll5046 316 aa protein NP_942202.1 GI:38505581 [Synechocystis sp. PCC 6803] 49. sulfotransferase domain-containing protein 340 aa protein YP_680960.1 GI:110677953 [Roseobacter denitrificans OCh 114] 50. putative sulfotransferase 271 aa protein ZP_03574132.1 GI:221201092 [Burkholderia multivorans CGD2M] 51. sulfotransferase 317 aa protein YP_003146110.1 GI:256822147 [Kangiella koreensis DSM 16069] 52. Protein-tyrosine sulfotransferase 381 aa protein EGI65733.1 GI:332025570 [Acromyrmex echinatior] 53. sulfotransferase 325 aa protein YP_004602624.1 GI:336322657 [Flexistipes sinusarabici DSM 4947] 54. nodulation protein noeE 433 aa protein YP_420424.1 GI:83310160 [Magnetospirillum magneticum AMB-1] 55. glycosyl transferase family 2 421 aa protein YP_003945463.1 GI:310640705 [Paenibacillus polymyxa SC2] 56. protein-tyrosine sulfotransferase 2 423 aa protein CCC84070.1 GI:343095861 [Paenibacillus polymyxa Ml] 57. sulfotransferase 346 aa protein ZP_01884054.1 GI:149277914 [Pedobacter sp. BAL39] 58. sulfotransferase: SEC-C motif protein 333 aa protein ZP_08568256.1 GI:336313314 [Shewanella sp. HN-41) 59. sulfotransferase domain protein 344 aa protein ZP_08430778.1 GI:332710841 [Lyngbya majuscula 3L] 60. sulfotransferase domain-containing 325 aa protein EGF25969.1 GI:327539348 protein [Rhodopirellula baltica WH47] 61. hypothetical protein MettrDRAFT_3778 396 aa protein ZP_06890062.1 GI:296448163 [Methylosinus trichosporium OB3b] 62. PREDICTED: MGC82552 protein-like 436 aa protein XP_002733820.1 GI:291227699 [Saccoglossus kowalevskii] 63. Sulfotransferase domain superfamily 318 aa protein ZP_05029988.1 GI:254416234 [Microcoleus chthonoplastes PCC 7420] 64. tyrosylprotein sulfotransferase-2 356 aa protein NP_001187093.1 GI:318064902 [Ictalurus punctatus] 65. family 2 glycosyl transferase 1043 aa protein YP_003528062.1 GI:292492623 [Nitrosococcus halophilus Nc4] 66. PREDICTED: protein-tyrosine 380 aa protein XP_624657.2 GI:328780257 sulfotransferase [Apis mellifera] 67. tyrosine sulfotransferase 395 aa protein XP_001864662.1 GI:170057846 [Culex quinquefasciatus] 68. hypothetical protein L8106_07576 281 aa protein ZP_01622104.1 GI:119489297 [Lyngbya sp. PCC 8106] 69. hypothetical protein NIDE3002 375 aa protein YP_003798623.1 GI:302038301 [Candidatus Nitrospira defluvii] 70. SecC motif-containing protein 342 aa protein YP_749583.1 GI:114562070 [Shewanella frigidimarina NCIMB 400] 71. sulfotransferase 294 aa protein YP_001519982.1 GI:158338805 [Acaryochloris marina MBIC11017] 72. protein-tyrosine sulfotransferase 2 356 aa protein NP_956713.1 GI:41056257 [Danio rerio] 73. PREDICTED: protein-tyrosine 380 aa protein XP_003394254.1 GI:340711379 sulfotransferase-like [Bombus terrestris] 74. GG17794 504 aa protein XP_001978257.1 GI:194895457 [Drosophila erecta] 75. hypothetical protein Swit_1252 308 aa protein YP_001261755.1 GI:148554173 [Sphingomonas wittichii RW1] 76. putative enzyme 305 aa protein ZP_01618957.1 GI:119484340 [Lyngbya sp. PCC 8106] 77. sulfotransferase 344 aa protein YP_722339.1 GI:113476278 [Trichodesmium erythraeum IMS101] 78. transport and golgi organization 13, 346 aa protein NP_001096973.1 GI:161077803 isoform C [Drosophila melanogaster] 79. hypothetical protein 454 aa protein XP_002590725.1 GI:260791416 BRAFLDRAFT_89531 [Branchiostoma floridae] 80. hypothetical protein L8106_19296 318 aa protein ZP_01620966.1 GI:119487094 [Lyngbya sp. PCC 8106) 81. TyrosylProtein SulfoTransferase 380 aa protein NP_499646.3 GI:71992370 family member (tpst-1) [Caenorhabditis elegans] 82. methionine biosynthesis protein 1039 aa protein ZP_05048086.1 GI:254434578 MetW, putative [Nitrosococcus oceani AFC27] 83. tyrosylprotein sulfotransferase 2 375 aa protein NP_001088427.1 GI:148235112 [Xenopus laevis] 84. glycosyl transferase family protein 1037 aa protein YP_343263.1 GI:77164738 [Nitrosococcus oceani ATCC 19707] 85. GM17618 478 aa protein XP_002042697.1 GI:195352394 [Drosophila sechellia] 86. GE17090 508 aa protein XP_002100486.1 GI:195478327 [Drosophila yakuba] 87. GI14854 459 aa protein XP_002010160.1 GI:195131443 [Drosophila mojavensis] 88. GD17135 501 aa protein XP_002106871.1 GI:195566606 [Drosophila simulans] 89. GF22576 498 aa protein XP_001965589.1 GI:194766965 [Drosophila ananassae] 90. transport and golgi organization 13, 499 aa protein NP_727717.1 GI:24641809 isoform B [Drosophila melanogaster] 91. GL20242 515 aa protein XP_002023360.1 GI:195165053 [Drosophila persimilis] 92. PREDICTED: protein-tyrosine 392 aa protein XP_001942867.2 GI:328706076 sulfotransferase-like [Acyrthosiphon pisum] 93. PREDICTED: similar to MGC82552 379 aa protein XP_415794.2 GI:118100226 protein [Gallus gallus] 94. protein-tyrosine sulfotransferase A 384 aa protein XP_003139556.1 GI:312073519 [Loa loa] 95. GA26942 [Drosophila 521 aa protein XP_001354726.2 GI:198468492 pseudoobscura pseudoobscura] 96. GK16105 466 aa protein XP_002067611.1 GI:195439384 [Drosophila willistoni] 97. PREDICTED: protein-tyrosine 396 aa protein XP_001606792.1 GI:156543274 sulfotransferase-like [Nasonia vitripennis] 98. PREDICTED: protein-tyrosine 450 aa protein XP_001362570.2 GI:334324786 sulfotransferase 1-like [Monodelphis domestica] 99. predicted protein 272 aa protein XP_001630972.1 GI:156378079 [Nematostella vectensis] 100. AGAP000900-PA 392 aa protein EAA12079.6 GI:333469474 [Anopheles gambiae str. PEST]

TABLE 4 List of proteins/peptides comprising a CurM-like TE domain. Ref. Protein/peptide No. of amino acid [organism or source] residues Accession No. 37. hypothetical protein lpl0509 282 aa protein YP_125875.1 GI:54293460 [Legionella pneumophila str. Lens] 38. putative lipase LipA 282 aa protein AAM73852.1 GI:21666982 [Legionella pneumophila 130b] 39. Alpha/beta hydrolase 294 aa protein ZP_08648517.1 GI:339055924 [gamma proteobacterium IMCC2047] 40. hypothetical protein lpp0533 282 aa protein YP_122871.1 GI:54296502 [Legionella pneumophila str. Paris] 41. Putative hydrolase or acyltransferase of 279 aa protein ZP_08572335.1 GI:336317483 alpha/beta superfamily [Rheinheimera sp. A13L] 42. lipase A 283 aa protein YP_094512.1 GI:52840713 [Legionella pneumophila subsp. pneumophila str. Philadelphia 1] 43. alpha/beta fold family hydrolase 288 aa protein NP_718168.1 GI:24374125 [Shewanella oneidensis MR-1] 44. alpha/beta hydrolase 300 aa protein YP_002798221.1 GI:226943148 [Azotobacter vinelandii DJ] 45. lipase 284 aa protein EGH20834.1 GI:330888173 [Pseudomonas syringae pv. mori str. 301020] 46. alpha/beta hydrolase fold protein 288 aa protein EGW60665.1 GI:345129761 [Dechlorosoma suillum PS] 47. hydrolase, alpha/beta fold family 291 aa protein ZP_01900040.1 GI:149911422 [Moritella sp. PE36] 48. lipase 284 aa protein EGH85562.1 GI:330987459 [Pseudomonas syringae pv. lachrymans str. M301315] 49. lipase 284 aa protein EGH90697.1 GI:331010641 [Pseudomonas syringae pv. tabaci ATCC 11528] 50. Alpha/beta hydrolase fold 284 aa protein YP_235108.1 GI:66045267 [Pseudomonas syringae pv. syringae B728a] 51. serine hydrolase-like 2 304 aa protein NP_001079604.1 GI:147899135 [Xenopus laevis] 52. Alpha/beta hydrolase fold protein 284 aa protein EGH30625.1 GI:330899206 [Pseudomonas syringae pv. japonica str. M301072PT] 53. alpha/beta hydrolase fold protein 291 aa protein YP_001674055.1 GI:167623761 [Shewanella halifaxensis HAW-EB4] 54. lipase 284 aa protein EGH02171.1 GI:330867462 [Pseudomonas syringae pv. aesculi str. 0893_23] 55. Alpha/beta hydrolase fold protein 284 aa protein EGH09818.1 GI:330875669 [Pseudomonas syringae pv. morsprunorum str. M302280PT] 56. putative hydrolase 308 aa protein ZP_01616002.1 GI:119475649 [marine gamma proteobacterium HTCC2143] 57. alpha/beta fold family hydrolase 284 aa protein EGH65633.1 GI:330965373 [Pseudomonas syringae pv. actinidiae str. M302091] 58. putative alpha/beta hydrolase 290 aa protein YP_003545632.1 GI:294012172 [Sphingobium japonicum UT26S] 59. Alpha/beta hydrolase fold protein 284 aa protein EGH78853.1 GI:330980750 [Pseudomonas syringae pv. aptata str. DSM 50252] 60. Alpha/beta hydrolase fold protein 284 aa protein EGH43451.1 GI:330940344 [Pseudomonas syringae pv. pisi str. 1704B] 61. Alpha/beta hydrolase fold protein 284 aa protein ZP_06500867.1 GI:289679977 [Pseudomonas syringae pv. syringae FF5] 62. hydrolase [gamma proteobacterium 299 aa protein ZP_04957287.1 GI:254282319 NOR51-B] 63. predicted Hydrolase or acyltransferase 305 aa protein ZP_01893017.1 GI:149375245 (alpha/beta hydrolase superfamily) protein [Marinobacter algicola DG893] 64. lipase A 281 aa protein ZP_06187778.1 GI:270159122 [Legionella longbeachae D-4968] 65. alpha/beta hydrolase fold protein 284 aa protein ZP_07774389.1 GI:312959874 [Pseudomonas fluorescens WH6] 66. alpha/beta hydrolase fold protein 300 aa protein YP_004387755.1 GI:330824452 [Alicycliphilus denitrificans K601] 67. hydrolase 322 aa protein YP_001615653.1 GI:162453286 [Sorangium cellulosum ‘So ce 56’] 68. alpha/beta fold family hydrolase 296 aa protein YP_003557221.1 GI:294141243 [Shewanella violacea DSS12] 69. lipase 284 aa protein YP_274221.1 GI:71736540 [Pseudomonas syringae pv. phaseolicola 1448A] 70. putative esterase 293 aa protein BAI49930.1 GI:269913831 [uncultured microorganism] 71. alpha/beta fold family hydrolase 298 aa protein YP_001982425.1 GI:192359104 [Cellvibrio japonicus Ueda107] 72. alpha/beta hydrolase fold protein 287 aa protein YP_004474637.1 GI:333900764 [Pseudomonas fulva 12-X] 73. alpha/beta hydrolase 283 aa protein YP_003810829.1 GI:304311231 [gamma proteobacterium HdN1] 74. putative hydrolase 249 aa protein YP_117116.1 GI:54022874 [Nocardia farcinica IFM 10152] 75. alpha/beta hydrolase fold protein 289 aa protein YP_003269090.1 GI:262197881 [Haliangium ochraceum DSM 14365] 76. Alpha/beta hydrolase fold protein 284 aa protein ZP_07264074.1 GI:302187401 [Pseudomonas syringae pv. syringae 642] 77. Alpha/beta hydrolase fold protein 310 aa protein ZP_01916760.1 GI:149928530 [Limnobacter sp. MED105] 78. putative lipase LipA 280 aa protein ZP_05108808.1 GI:254495899 [Legionella drancourtii LLAP12] 79. hydrolase, alpha/beta fold family 284 aa protein ZP_03396309.1 GI:213968164 [Pseudomonas syringae pv. tomato T1] 80. alpha/beta hydrolase fold protein 340 aa protein NP_946347.1 GI:39934071 [Rhodopseudomonas palustris CGA009] 81. lipase, putative 284 aa protein EFW80985.1 GI:320324913 [Pseudomonas syringae pv. glycinea str. B076] 82. alpha/beta fold family hydrolase 284 aa protein NP_792039.1 GI:28869420 [Pseudomonas syringae pv. tomato str. DC3000] 83. hydrolase or acytransferase 300 aa protein YP_933620.1 GI:119898407 [Azoarcus sp. BH72] 84. alpha/beta superfamily hydrolase 293 aa protein YP_002311621.1 GI:212635096 [Shewanella piezotolerans WP3] 85. putative hydrolase 292 aa protein YP_158988.1 GI:56477399 [Aromatoleum aromaticum EbN1] 86. putative hydrolase 284 aa protein YP_002871482.1 GI:229589363 [Pseudomonas fluorescens SBW25] 87. alpha/beta hydrolase fold protein 289 aa protein YP_001990203.1 GI:192289598 [Rhodopseudomonas palustris TIE-1] 88. hydrolase 286 aa protein NP_250313.1 GI:15596819 [Pseudomonas aeruginosa PAO1] 89. putative hydrolase 286 aa protein ZP_07792860.1 GI:313106637 [Pseudomonas aeruginosa 39016] 90. hydrolase, alpha/beta fold family 286 aa protein ZP_01223987.1 GI:90416054 protein [marine gamma proteobacterium HTCC2207] 91. PA1622 287 aa protein AAT50924.1 GI:49083048 [synthetic construct] 92. lipase 284 aa protein EGH59298.1 GI:330959038 [Pseudomonas syringae pv. maculicola str. ES4326] 93. hydrolase 282 aa protein AEA83820.1 GI:327480510 [Pseudomonas stutzeri DSM 4166] 94. alpha/beta hydrolase 289 aa protein YP_574516.1 GI:92114588 [Chromohalobacter salexigens DSM 3043] 95. alpha/beta hydrolase fold 306 aa protein YP_958843.1 GI:120554492 [Marinobacter aquaeolei VT8] 96. hydrolase 285 aa protein YP_001172415.1 GI:146282262 [Pseudomonas stutzeri A1501] 97. Hydrolase or acetyltransferase 287 aa protein YP_001964755.1 GI:189912866 [Leptospira biflexa serovar Patoc strain ‘Patoc 1 (Ames)’] 98. hypothetical hydrolase/acyltransferase 299 aa protein ZP_01219631.1 GI:90411621 [Photobacterium profundum 3TCK] 99. putative hydrolase 286 aa protein YP_001349005.1 GI:152984242 [Pseudomonas aeruginosa PA7] 100. hydrolase 289 aa protein ZP_04576152.1 GI:237745672 [Oxalobacter formigenes HOxBLS]

In some embodiments of the invention, a precursor molecule, such as propionate or acrylate, is provided to the PKS to produce a polyketide of interest. The precursor molecule can be fed or exogenously provided to or endogenously produced by the host cell comprising the PKS, or the host cell can produce the enzymes capable of biosynthesizing the precursor molecule from a simpler molecule that can be fed or exogenously provided to the host cell or the host cell naturally endogenously produces. For example, Streptomyces species produces propionyl-CoA as part of its innate metabolism, thus eliminating the need for exogenous propionate provision.

In some embodiments of the invention, the PKS capable of producing an α-olefin of interest comprises CurM, the terminal PKS from the curacin biosynthesis pathway (Chang, 2004) or a similar module. CurM is a monomodular PKS protein containing an unusual sulfotransferase domain. This domain sulfonates the beta hydroxyl group of the penultimate product and the combination of the ST-TE domains catalyze a decarboxylation and functional dehydration (with sulfate as the leaving group) to yield the terminal olefin. FIG. 1 illustrates how domains from CurM can be coupled to other PKS enzymes to produce an α-olefin, such as 1-hexene, in accordance with the methods and materials of the invention. In the example shown in FIG. 1, first PKS ORF encodes a loading module specific for propionate (via the CoA) and an extension module that incorporates acetate (via malonyl-CoA) and fully reduces the β-carbonyl. In this example shown in FIG. 1, the loading domain is from the erythromycin PKS (Donadio et al. 1991. Science 675-679; incorporated herein by reference) and module 5 is from the nystatin PKS (Brautaset et al. 2000. Chemistry & Biology 7:395-403; incorporated herein by reference), but there are other modules that can be used to provide the same product. The second and third proteins that constitute the multi-subunit PKS in this example come from the curacin PKS and corresponding gene cluster (see Chang et al. 2004. Journal of Natural Products 67:1356-1367; sequence updated in Gu et al. J Am Chem. Soc. 2009 Nov. 11; 131(44):16033-5; both of which are incorporated herein by reference). Using this PKS, the first two modules can be replaced with any of several well characterized modules to yield several dozen different α-olefins. Increasing the number of upstream modules to three or more increases the number of different products into the hundreds and higher.

To ensure appropriate interactions between the two PKS proteins in this and related examples, one can use the acyl-carrier protein (ACP) and C-terminus from CurM's native enzyme partner, CurL. In general, native C- and N-terminal docking partners can be used in the combinatorial PKS enzymes of the invention. Other cognate domains from different PKS enzymes can also be used.

FIG. 3A shows an exemplary PKS for producing a triketide α-olefin. FIGS. 3B and 3C show exemplary extensions of this model, demonstrating how additional modules can be employed to yield longer, fully saturated, linear α-olefins.

Incorporation of the avermectin loading domain into a PKS of the invention provides access to a number of other α-olefins. Some examples of this aspect of the invention to make both known and novel α-olefins are shown in FIG. 4.

In some embodiments, the PKS of the invention produces a butadiene with a pendant acid moiety, such that the butadiene is suitable for subsequent crosslinking. FIG. 5 shows such a PKS that comprises a set of enzymes comprising an HMG-like system found in several PKS enzymes and corresponding gene clusters. This system converts the fl-carbonyl to a number of different chemical moieties, most pertinently an exomethylene. Briefly, one of the previously described systems for incorporating an acrylate starter (DEBS (Donadio et al. 1991. supra) or difficidin (Chen et al. 2006. J. Bacteriol. 188(11):4024-36; incorporated herein by reference) loading module) can be fused to an HMG-like module, such as JamE from the jamaicamide cluster (Edwards et al. 2004. ChemBiol. 11(6):817-33; incorporated herein by reference), and a TE domain at the C-terminus. Such a bimodular PKS enzyme can be co-expressed with the genes encoding accessory proteins required for the incorporation of the desired chemistry. In this example these enzymes are JamH, JamG and JamI (Edwards et al., 2004, supra).

In some embodiments of the invention, the PKS comprises a CurM chain termination module of Lyngbya majuscula CurM or functionally equivalent module. In some embodiments of the invention, the PKS comprises the ST and TE domains of the curM chain termination module and sequences derived from a different CurM module or another PKS entirely. In some embodiments of the invention, the PKS comprises the KR, ACP, ST and TE domains of the CurM chain termination module and sequences derived from a different CurM module or another PKS entirely. In some embodiments of the invention, the PKS comprises the AT, KR, ACP, ST and TE domains of the CurM chain termination module and sequences derived from a different CurM module or another PKS entirely.

In some embodiments, the PKS of the invention comprises an acrylate loading module, such as the acrylate loading module from the dificidin PKS (Chen et al., 2006, supra), which incorporates the acrylyl moiety from a hydroxypropionate precursor involving the enzymes difA-E.

The present invention also provides a PKS comprising an acrylate loading module coupled to a thioesterase domain, wherein the PKS is capable of producing acrylate (acrylic acid). The erythromycin PKS, for example and without limitation, includes suitable such modules and domains.

The following depict the amino acid sequences of SEQ ID NO:1-9

L. majuscula CurM (GenBank: ACV42478.1) has the following amino acid sequence (SEQ ID NO:1):

1 msnvskttqq dvssqevlqv lqemrsrlea vnkaktepia ivgmacrfpg gandpstywr 61 llhdgidait pvpphrwdvn ahyepnpeip gkaytkqggf iegvdqfdpl ffgispreai 121 sldpqyrlll evtwealena gqtwtnlkns ktsvfmgvst ddyaslsnpi linnrslgvg 181 rishllglqg sniqldtacs sslvaihlac qs1rsgesnl alvggvnlil spistigrct 241 mkalspdgrc ktfdaaangy gqaegcgvvv lkrlsdaitd gdlisalirg sainhdgpss 301 gltvpngmaq kqviqqalsn arlephqvsy leahgtgtal gdpieieala aiygknrpvd 361 qplvvgsvkt nighleaaag vsalikvvla lqhgeipphl hlkqpnpyvd wdklpikipt 421 slmpwnceak priagissfg isgtnahlll eevpelikgq kakgksendl erplhiltls 481 tktekaleel vsryqnhwet ypelaisdvc ytantgraqf nhrlaviasg seeltqklrq 541 htageevvgv fsgkvpnsgs eskvaflftg ggsqylnmgr qlyetqptfr qaldtcdhil 601 rpyldnplle ilypqdaqks ndspldqtgy tqpalfsiey allklweswg ikpnvvmghs 661 vgeyvaatva gvfsledglk liaargrlmq glpaggemvs vmaseskvle tlkamsledk 721 vaiaaingpe sivisgeaea iramathles vgiktkqlqv shafhsplme pmlaefeava 781 nqityhqpri piisnvtgtk adksiataqy wvnhvrqpvr faqgmatlhq qgyetfleig 841 akpillgmgk qclspdvgvw lpslrhgvde wqqilsslgq lyvqgakvdw sgfdrdysre 901 kvvlptypfq rerywvetsi nqqqvvcsge pnlqgtpegt sttivkllsq gntkelaekv 961 ektsdlppeq lkllpdllas lsqqhqqela rlttkkwfyk vqwisqaikp qrnksnnqvc 1021 hwliltdskg lgkslathlq qlgnecsvvy qadnyqnyep giyhinpshp qefeqvyqti 1081 fengklplqk vihlwsldta seqdlttetl eqaqlwgcgs tlhllqtivk npnstppklw 1141 mitrgtqpvl sptekltvat splwglgrti asehpqlwgg lvdldpqgse devevllqqi 1201 idsqkedhla vrnrkiyvar llkhipqesq plslrsdaty litgglgalg lktaawmaek 1261 garnlvlisr rqpseqaqqt iqsleelgtq vkvlsadisv esdvanileq igtslppllg 1321 vihaagvldd gllqqtnwer ftkvmapkvn gtwnlhkltq hlsldffvcf ssmssllgsp 1381 gqgnyaaana fmdavvhyrr emglpglsin wggwseggma trlasqhqnr mqtagislis 1441 peqgiqvlee lvrtqstaqv gvlpvdwsvl akqfssanps slllellqqe tssektderi 1501 leklqaapit erqdilknyi qlvvaktlgi npskistddn fvelgmdslm gmevvnklsg 1561 dldfiiypre fyerptidsl tqylsaelse dnlatqpspt sleifatkss psgnsarpas 1621 vssrlpgiif ilssprsgst llrvmlaghs slfsppelhl lpfntmkerq eqlnlsylge 1681 glqktfmevk nldatasgal ikdlesqnls iqqvygmlqe niaprllvdk sptyamepti 1741 lergealfan skyiylvrhp ysviesfvrm rmqklvglge enpyrvaeqv waksnqniln 1801 flsqleperq hqiryedlvk kpqqvlsqlc dflnvpfepe llqpyqgdrm tggvhqksls 1861 isdpnflkhn tidesladkw ktiqlpyplk setqriasql syelpnlvtt ptnqqpqvst 1921 tpsteqpime ekflefggnq icicswgspe hpvvlcihgi leqglawqev alplaaqgyr 1981 vvapdlfghg rsshlemvts yssltflaqi drvigelpdq plllvghsmg amlataiasv 2041 rpkkikelil velplpaees kkesavnqlt tcldylsstp qhpifpdvat aasrlrqaip 2101 slseefsyil agritqpnqg gvrwswdaii rtrsilglnn lpggrsqyle mlksiqvptt 2161 lvygdsskln rpedlqqqkm tmtqakrvfl sgghnlhida aaalaslilt s

HexORF1 has the following amino acid sequence (SEQ ID NO:2):

MADLSKLSDSRTAQPGRIVRPWPLSGCNESALRARARQLRAHLDRFPDAG VEGVGAALAHDEQADAGPHRAVVVASSTSELLDGLAAVADGRPHASVVRG VARPSAPVVFVFPGQGAQWAGMAGELLGESRVFAAAMDACARAFEPVTDW TLAQVLDSPEQSRRVEVVQPALFAVQTSLAALWRSFGVTPDAVVGHSIGE LAAAHVCGAAGAADAARAAALWSREMIPLVGNGDMAAVALSADEIEPRIA RWDDDVVLAGVNGPRSVLLTGSPEPVARRVQELSAEGVRAQVINVSMAAH SAQVDDIAEGMRSALAWFAPGGSEVPFYASLTGGAVDTRELVADYWRRSF RLPVRFDEAIRSALEVGPGTFVEASPHPVLAAALQQTLDAEGSSAAVVPT LQRGQGGMRRFLLAAAQAFTGGVAVDWTAAYDDVGAEPGSLPEFAPAEEE DEPAESGVDWNAPPHVLRERLLAVVNGETAALAGREADAEATFRELGLDS VLAAQLRAKVSAAIGREVNIALLYDHPTPRALAEALAAGTEVAQRETRAR TNEAAPGEPVAVVAMACRLPGGVSTPEEFWELLSEGRDAVAGLPTDRGWD LDSLFHPDPTRSGTAHQRGGGFLTEATAFDPAFFGMSPREALAVDPQQRL MLELSWEVLERAGIPPTSLQASPTGVFVGLIPQEYGPRLAEGGEGVEGYL MTGTTTSVASGRIAYTLGLEGPAISVDTACSSSLVAVHLACQSLRRGESS LAMAGGVTVMPTPGMLVDFSRMNSLAPDGRCKAFSAGANGFGMAEGAGML LLERLSDARRNGHPVLAVLRGTAVNSDGASNGLSAPNGRAQVRVIQQALA ESGLGPADIDAVEAHGTGTRLGDPIEARALFEAYGRDREQPLHLGSVKSN LGHTQAAAGVAGVIKMVLAMRAGTLPRTLHASERSKEIDWSSGAISLLDE PEPWPAGARPRRAGVSSFGVSGTNAHVIVEEAPESSADAVAESGVRVPVP VVPWVVSARSAEGLAAQAERLARFVGERSDQDPVDIGFSLVRSRSLLEHR AVVLGKGRDDLVAGLASLASDGSATGVVSGVARGRARVAFGFSGQGAQRV GMGAELASVYPVFAEALAEVTGALGLDPEVFGDVDRLGRTEVTQAALFAF EVAVVRLLESFGVRPDVLIGHSIGEIAAAYVAGVFSLGDAAALVGARGRL MQALPAGGVMVAVQAGEAEVVAALEGFADRVSLAAVNGPSSVVVSGEAEA VEQVVARLGKVKSKRLRVSHAFHSPLMEPMLADFRQVAEQITYNEPQLPV VSNVSGRLAEPGELTTPDYWVRHVREAVRFGDGVRALAADGVGVLVEVGP DSVLTALARESLDGEDGLRAVPLLRKDRPEPETLLTGVAQAFTHGVQVDW PALLPGGRRVELPTYAFQRRRYWLEDADPTGGDPAALGLTAADHPLLGAA VPLAEDQGIVITSRLSLRTHPWLADHEIGGTVLLPGAGLVEIALRAGDEV GCGRVEELTLEIPLVVPQEGGVTVQIRVGAPDESGWRPMTVHSRTDPEEE WTRHVSGVLSPDVPTERYDLGAWPPAGATPVELDGFYEAYARLGYAYGPS FQGLRAAWRRGDEVFAEVSLPVEEQETAGRFTLHPALLDAALQSAGAGAF FDSGGSMRLPFAWSGVSVFAAGASTVRVRLSPAGPDAVTVALADPTGAPV ALVERLLIPEMSPEQLERVRGEEKEAPYVLDWVPVEVPADDLVRPERWTL LGGADAGVGLDVAGAFASLEPSDGAPEFVVLPCVPPTSPTRAADVRQSTL QALTVLQNWVTDERHADSRLVLVTRRAVGVGAHDDVPDLTHAALWGLVRS AQTENPGRFLLVDLDEGAELAEVLPGALGSGESQVAVRAGRVLAARLARS GSGGAELVPPAGAPWRLDTTSPGTLENLALVPSAEEPLGPLDVRVSVRAA GLNFRDVLIALGMYPGDARMGGEGAGVVTDVGSEVTTLAPGDRVMGMLSS AFGPTAVSDHRALVRVPDDWSFEQAASVPTVFATAYYGLVDLAELRAGQS VLVHAAAGGVGMAAVQLARHLGAEVFGTASTGKWDSLRAGGLDAEHIASS RTVEFEETFLAATAGRGVDVVLDSLAGEFVDASLRLLPRGGRFVEMGKAD IRDAERVAADHPGVTYRSFDLLEAGLDRFQEILTEVVRLFERGVLRHLPV TAWDVRRAAEAFRFVSQARHVGKNVLVMPRVWDRDGTVLITGGTGALGAL VARHLVAEHGMRNVLLAGRRGVDAPGARELLAELETAGAQVSVVACDVAD RDAVAELIAKVPVEHPLTAVVHTAGVVADATLTALDAERVDTVLRAKVDA VLHLHEATRGLDLAGFVLFSSASGIFGSPGQGNYAAANSFIDAFAHHRRA QGLPALSLAWGLWARTSGMAGQLGHDDVARISRTGLAPITDDQGMALLDA ALGAGRPLLVPVRLDRAALRSQATAGTLPPILRGLVRATVRRAASTAAAQ GPSLAERLAGLPVTEHERIVVELVRADLAAVLGHSSSAGIDPGRAFQDMG IDSLTAVELRNRLNGATGLRLAASLVFDYPTPNALATHILDELALDTAGA GAAGEPDGPAPAPADEARFRRVINSIPLDRIRRAGLLDALLGLAGTSADT AASDDFDQEEDGPAIASMDVDDLVRIALGESDTTADITEGTDRS*

HexORF1′ has the following amino acid sequence (SEQ ID NO:3):

MADLSKLSDSRTAQPGRIVRPWPLSGCNESALRARARQLRAHLDRFPDAG VEGVGAALAHDEQADAGPHRAVVVASSTSELLDGLAAVADGRPHASVVRG VARPSAPVVFVFPGQGAQWAGMAGELLGESRVFAAAMDACARAFEPVTDW TLAQVLDSPEQSRRVEVVQPALFAVQTSLAALWRSFGVTPDAVVGHSIGE LAAAHVCGAAGAADAARAAALWSREMIPLVGNGDMAAVALSADEIEPRIA RWDDDVVLAGVNGPRSVLLTGSPEPVARRVQELSAEGVRAQVINVSMAAH SAQVDDIAEGMRSALAWFAPGGSEVPFYASLTGGAVDTRELVADYWRRSF RLPVRFDEAIRSALEVGPGTFVEASPHPVLAAALQQTLDAEGSSAAVVPT LQRGQGGMRRFLLAAAQAFTGGVAVDWTAAYDDVGAEPGSLPEFAPAEEE DEPAESGVDWNAPPHVLRERLLAVVNGETAALAGREADAEATFRELGLDS VLAAQLRAKVSAAIGREVNIALLYDHPTPRALAEALAAGTEVAQRETRAR TNEAAPGEPVAVVAMACRLPGGVSTPEEFWELLSEGRDAVAGLPTDRGWD LDSLFHPDPTRSGTAHQRGGGFLTEATAFDPAFFGMSPREALAVDPQQRL MLELSWEVLERAGIPPTSLQASPTGVFVGLIPQEYGPRLAEGGEGVEGYL MTGTTTSVASGRIAYTLGLEGPAISVDTACSSSLVAVHLACQSLRRGESS LAMAGGVTVMPTPGMLVDFSRMNSLAPDGRCKAFSAGANGFGMAEGAGML LLERLSDARRNGHPVLAVLRGTAVNSDGASNGLSAPNGRAQVRVIQQALA ESGLGPADIDAVEAHGTGTRLGDPIEARALFEAYGRDREQPLHLGSVKSN LGHTQAAAGVAGVIKMVLAMRAGTLPRTLHASERSKEIDWSSGAISLLDE PEPWPAGARPRRAGVSSFGVSGTNAHVIVEEAPESSADAVAESGVRVPVP VVPWVVSARSAEGLAAQAERLARFVGERSDQDPVDIGFSLVRSRSLLEHR AVVLGKGRDDLVAGLASLASDGSATGVVSGVARGRARVAFGFSGQGAQRV GMGAELASVYPVFAEALAEVTGALGLDPEVFGDVDRLGRTEVTQAALFAF EVAVVRLLESFGVRPDVLIGHSIGEIAAAYVAGVFSLGDAAALVGARGRL MQALPAGGVMVAVQAGEAEVVAALEGFADRVSLAAVNGPSSVVVSGEAEA VEQVVARLGKVKSKRLRVSHAFHSPLMEPMLADFRQVAEQITYNEPQLPV VSNVSGRLAEPGELTTPDYWVRHVREAVRFGDGVRALAADGVGVLVEVGP DSVLTALARESLDGEDGLRAVPLLRKDRPEPETLLTGVAQAFTHGVQVDW PALLPGGRRVELPTYAFQRRRYWLEDADPTGGDPAALGLTAADHPLLGAA VPLAEDQGIVITSRLSLRTHPWLADHEIGGTVLLPGAGLVEIALRAGDEV GCGRVEELTLEIPLVVPQEGGVTVQIRVGAPDESGWRPMTVHSRTDPEEE WTRHVSGVLSPDVPTERYDLGAWPPAGATPVELDGFYEAYARLGYAYGPS FQGLRAAWRRGDEVFAEVSLPVEEQETAGRFTLHPALLDAALQSAGAGAF FDSGGSMRLPFAWSGVSVFAAGASTVRVRLSPAGPDAVTVALADPTGAPV ALVERLLIPEMSPEQLERVRGEEKEAPYVLDWVPVEVPADDLVRPERWTL LGGADAGVGLDVAGAFASLEPSDGAPEFVVLPCVPPTSPTRAADVRQSTL QALTVLQNWVTDERHADSRLVLVTRRAVGVGAHDDVPDLTHAALWGLVRS AQTENPGRFLLVDLDEGAELAEVLPGALGSGESQVAVRAGRVLAARLARS GSGGAELVPPAGAPWRLDTTSPGTLENLALVPSAEEPLGPLDVRVSVRAA GLNFRDVLIALGMYPGDARMGGEGAGVVTDVGSEVTTLAPGDRVMGMLSS AFGPTAVSDHRALVRVPDDWSFEQAASVPTVFATAYYGLVDLAELRAGQS VLVHAAAGGVGMAAVQLARHLGAEVFGTASTGKWDSLRAGGLDAEHIASS RTVEFEETFLAATAGRGVDVVLDSLAGEFVDASLRLLPRGGRFVEMGKAD IRDAERVAADHPGVTYRSFDLLEAGLDRFQEILTEVVRLFERGVLRHLPV TAWDVRRAAEAFRFVSQARHVGKNVLVMPRVWDRDGTVLITGGTGALGAL VARHLVAEHGMRNVLLAGRRGVDAPGARELLAELETAGAQVSVVACDVAD RDAVAELIAKVPVEHPLTAVVHTAGVVADATLTALDAERVDTVLRAKVDA VLHLHEATRGLDLAGFVLFSSASGIFGSPGQGNYAAANSFIDAFAHHRRA QGLPALSLAWGLWARTSGMAGQLGHDDVARISRTGLAPITDDQGMALLDA ALGAGRPLLVPVRLDRAALRSQATAGTLPPILRGLVRATVRRAASTAAAQ GPSLAERLAGLPVTEHERIVVELVRADLAAVLGHASAERVPADQAFAELG VDSLTAVELRNRLNGATGLRLAASLVFDYPTPNALATHILDELALDTAGA GAAGEPDGPAPAPADEARFRRVINSIPLDRIRRAGLLDALLGLAGTSADT AASDDFDQEEDGPAIASMDVDDLVRIALGESDTTADITEGTDRS*

HexORF2 has the following amino acid sequence (SEQ ID NO:4):

MSSASSEKIVEALRASLTENERLRRLNQELAAAAHEPVAIVSMACRFP GGVESPEDFWDLISEGRDAVSGLPDNRGWDLDALYDPDPEAQGKTYVR EGAFLYDAAEFDAELFGISPREALAMDPQQRLLMETSWEVLERAGIRP DSLRGKPVGVFTGGITSDYVTRHYASGTAPQLPSGVESHFMTGSAGSV FSGRIAYTYGFEGPAVTVDTACSSSLVALHMAAQSLRQGECSLAFAGG VAVLPNPGTFVGFSRQRALSPDGRCKAFSADADGTGWGEGAGLVLLEK LSDARRNGHPVLAILRGSAVNQDGASNGLTAPNGPSQQRVIRAALANA RLSPDDVDVVEAHGTGTPLGDPIEAQALQATYGRSRSAERPLWLGSVK SNVAHAQAAAGVASVIKVVMALRHRLLPKTLHADERSPHIDWHSGAVE LLTEAREWSRTEGRARRAGVSSFGISGTNAHVIIEEAPELIKGQKAKG KSENDLERPLHILTLSTKTEKALEELVSRYQNHWETYPELAISDVCYT ANTGRAQFNHRLAVIASGSEELTQKLRQHTAGEEVVGVFSGKVPNSGS ESKVAFLFTGQGSQYLNMGRQLYETQPTFRQALDTCDHILRPYLDNPL LEILYPQDAQKSNDSPLDQTGYTQPALFSIEYALLKLWESWGIKPNVV MGHSVGEYVAATVAGVFSLEDGLKLIAARGRLMQGLPAGGEMVSVMAS ESKVLETLKAMSLEDKVAIAAINGPESIVISGEAEAIRAMATHLESVG IKTKQLQVSHAFHSPLMEPMLAEFEAVANQITYHQPRIPIISNVTGTK ADKSIATAQYWVNHVRQPVRFAQGMATLHQQGYETFLEIGAKPILLGM GKQCLSPDVGVWLPSLRHGVDEWQQILSSLGQLYVQGAKVDWSGFDRD YSREKVVLPTYPFQRERYWVETSINQQQVVCSGEPNLQGTPEGTSTTI VKLLSQGNTKELAEKVEKTSDLPPEQLKLLPDLLASLSQQHQQELARL TTKKWFYKVQWISQAIKPQRNKSNNQVCHWLILTDSKGLGKSLATHLQ QLGNECSVVYQADNYQNYEPGIYHINPSHPQEFEQVYQTIFENGKLPL QKVIHLWSLDTASEQDLTTETLEQAQLWGCGSTLHLLQTLVKNPNSTP PKLWMITRGTQPVLSPTEKLTVATSPLWGLGRTIASEHPQLWGGLVDL DPQGSEDEVEVLLQQIIDSQKEDHLAVRNRKIYVARLLKHIPQESQPL SLRSDATYLITGGLGALGLKTAAWMAEKGARNLVLISRRQPSEQAQQT IQSLEELGTQVKVLSADISVESDVANILEQIQTSLPPLLGVIHAAGVL DDGLLQQTNWERFTKVMAPKVNGTWNLHKLTQHLSLDFFVCFSSMSSL LGSPGQGNYAAANAFMDAVVHYRREMGLPGLSINWGGWSEGGMATRLA SQHQNRMQTAGISLISPEQGIQVLEELVRTQSTAQVGVLPVDWSVLAK QFSSANPSSLLLELLQQETSSEKTDERILEKLQAAPITERQDILKNYI QLVVAKTLGINPSKISTDDNFVELGMDSLMGMEVVNKLSGDLDFIIYP REFYERPTIDSLTQYLSAELSEDNLATQPSPTSLEIFATKSSPSGNSA RPASVSSRLPGIIFILSSPRSGSTLLRVMLAGHSSLFSPPELHLLPFN TMKERQEQLNLSYLGEGLQKTFMEVKNLDATASQALIKDLESQNLSIQ QVYGMLQENIAPRLLVDKSPTYAMEPTILERGEALFANSKYIYLVRHP YSVIESFVRMRMQKLVGLGEENPYRVAEQVWAKSNQNILNFLSQLEPE RQHQIRYEDLVKKPQQVLSQLCDFLNVPFEPELLQPYQGDRMTGGVHQ KSLSISDPNFLKHNTIDESLADKWKTIQLPYPLKSETQRIASQLSYEL PNLVTTPTNQQPQVSTTPSTEQPIMEEKFLEFGGNQICLCSWGSPEHP VVLCIHGILEQGLAWQEVALPLAAQGYRVVAPDLFGHGRSSHLEMVTS YSSLTFLAQIDRVIQELPDQPLLLVGHSMGAMLATAIASVRPKKIKEL ILVELPLPAEESKKESAVNQLTTCLDYLSSTPQHPIFPDVATAASRLR QAIPSLSEEFSYILAQRITQPNQGGVRWSWDAIIRTRSILGLNNLPGG RSQYLEMLKSIQVPTTLVYGDSSKLNRPEDLQQQKMTMTQAKRVFLSG GHNLHIDAAAALASLILTS*

The amino acid sequence of a PKS capable of producing 1-butene has the following amino acid sequence (SEQ ID NO:5):

MADLSKLSDSRTAQPGRIVRPWPLSGCNESALRARARQLRAHLDRFPD AGVEGVGAALAHDEQADAGPHRAVVVASSTSELLDGLAAVADGRPHAS VVRGVARPSAPVVFVFPGQGAQWAGMAGELLGESRVFAAAMDACARAF EPVTDWTLAQVLDSPEQSRRVEVVQPALFAVQTSLAALWRSFGVTPDA VVGHSIGELAAAHVCGAAGAADAARAAALWSREMIPLVGNGDMAAVAL SADEIEPRIARWDDDVVLAGVNGPRSVLLTGSPEPVARRVQELSAEGV RAQVINVSMAAHSAQVDDIAEGMRSALAWFAPGGSEVPFYASLTGGAV DTRELVADYWRRSFRLPVRFDEAIRSALEVGPGTFVEASPHPVLAAAL QQTLDAEGSSAAVVPTLQRGQGGMRRFLLAAAQAFTGGVAVDWTAAYD DVGAEPGSLPEFAPAEEEDEPAESGVDWNAPPHVLRERLLAVVNGETA ALAGREADAEATFRELGLDSVLAAQLRAKVSAAIGREVNIALLYDHPT PRALAEALSSGTEVAQRETRARTNEAAPGEPIAVVAMACRLPGGVSTP EEFWELLSEGRDAVAGLPTDRGWDLDSLFHPDPTRSGTAHQRGGGFLT EATAFDPAFFGMSPREALAVDPQQRLMLELSWEVLERAGIPPTSLQAS PTGVFVGLIPQEYGPRLAEGGEGVEGYLMTGTTTSVASGRIAYTLGLE GPAISVDTACSSSLVAVHLACQSLRRGESSLAMAGGVTVMPTPGMLVD FSRMNSLAPDGRCKAFSAGANGFGMAEGAGMLLLERLSDARRNGHPVL AVLRGTAVNSDGASNGLSAPNGRAQVRVIQQALAESGLGPADIDAVEA HGTGTRLGDPIEARALFEAYGRDREQPLHLGSVKSNLGHTQAAAGVAG VIKMVLAMRAGTLPRTLHASERSKEIDWSSGAISLLDEPEPWPAGARP RRAGVSSFGISGTNAHAIIEEAPELIKGQKAKGKSENDLERPLHILTL STKTEKALEELVSRYQNHWETYPELAISDVCYTANTGRAQFNHRLAVI ASGSEELTQKLRQHTAGEEVVGVFSGKVPNSGSESKVAFLFTGQGSQY LNMGRQLYETQPTFRQALDTCDHILRPYLDNPLLEILYPQDAQKSNDS PLDQTGYTQPALFSIEYALLKLWESWGIKPNVVMGHSVGEYVAATVAG VFSLEDGLKLIAARGRLMQGLPAGGEMVSVMASESKVLETLKAMSLED KVAIAAINGPESIVISGEAEAIRAMATHLESVGIKTKQLQVSHAFHSP LMEPMLAEFEAVANQITYHQPRIPIISNVTGTKADKSIATAQYWVNHV RQPVRFAQGMATLHQQGYETFLEIGAKPILLGMGKQCLSPDVGVWLPS LRHGVDEWQQILSSLGQLYVQGAKVDWSGFDRDYSREKVVLPTYPFQR ERYWVETSINQQQVVCSGEPNLQGTPEGTSTTIVKLLSQGNTKELAEK VEKTSDLPPEQLKLLPDLLASLSQQHQQELARLTTKKWFYKVQWISQA IKPQRNKSNNQVCHWLILTDSKGLGKSLATHLQQLGNECSVVYQADNY QNYEPGIYHINPSHPQEFEQVYQTIFENGKLPLQKVIHLWSLDTASEQ DLTTETLEQAQLWGCGSTLHLLQTLVKNPNSTPPKLWMITRGTQPVLS PTEKLTVATSPLWGLGRTIASEHPQLWGGLVDLDPQGSEDEVEVLLQQ IIDSQKEDHLAVRNRKIYVARLLKHIPQESQPLSLRSDATYLITGGLG ALGLKTAAWMAEKGARNLVLISRRQPSEQAQQTIQSLEELGTQVKVLS ADISVESDVANILEQIQTSLPPLLGVIHAAGVLDDGLLQQTNWERFTK VMAPKVNGTWNLHKLTQHLSLDFFVCFSSMSSLLGSPGQGNYAAANAF MDAVVHYRREMGLPGLSINWGGWSEGGMATRLASQHQNRMQTAGISLI SPEQGIQVLEELVRTQSTAQVGVLPVDWSVLAKQFSSANPSSLLLELL QQETSSEKTDERILEKLQAAPITERQDILKNYIQLVVAKTLGINPSKI STDDNFVELGMDSLMGMEVVNKLSGDLDFIIYPREFYERPTIDSLTQY LSAELSEDNLATQPSPTSLEIFATKSSPSGNSARPASVSSRLPGIIFI LSSPRSGSTLLRVMLAGHSSLFSPPELHLLPFNTMKERQEQLNLSYLG EGLQKTFMEVKNLDATASQALIKDLESQNLSIQQVYGMLQENIAPRLL VDKSPTYAMEPTILERGEALFANSKYIYLVRHPYSVIESFVRMRMQKL VGLGEENPYRVAEQVWAKSNQNILNFLSQLEPERQHQIRYEDLVKKPQ QVLSQLCDFLNVPFEPELLQPYQGDRMTGGVHQKSLSISDPNFLKHNT IDESLADKWKTIQLPYPLKSETQRIASQLSYELPNLVTTPTNQQPQVS TTPSTEQPIMEEKFLEFGGNQICLCSWGSPEHPVVLCIHGILEQGLAW QEVALPLAAQGYRVVAPDLFGHGRSSHLEMVTSYSSLTFLAQIDRVIQ ELPDQPLLLVGHSMGAMLATAIASVRPKKIKELILVELPLPAEESKKE SAVNQLTTCLDYLSSTPQHPIFPDVATAASRLRQAIPSLSEEFSYILA QRITQPNQGGVRWSWDAIIRTRSILGLNNLPGGRSQYLEMLKSIQVPT TLVYGDSSKLNRPEDLQQQKMTMTQAKRVFLSGGHNLHIDAAAALASL ILTS*

The amino acid sequence of a PKS capable of producing propene has the following amino acid sequence (SEQ ID NO:6):

MAGHGDATAQKAQDAEKSEDGSDAIAVIGMSCRFPGAPGTAEFWQLLSSGADAVVTAADGRR RGTIDAPADFDAAFFGMSPREAAATDPQQRLVLELGWEALEDAGIVPESLRGEAASVFVGAM NDDYATLLHRAGAPTDTYTATGLQHSMIANRLSYFLGLRGPSLVVDTGQSSSLVAVALAVES LRGGTSGIALAGGVNLVLAEEGSAAMERVGALSPDGRCHTFDARANGYVRGEGGAIVVLKPL ADALADGDRVYCVVRGVATGNDGGGPGLTVPDRAGQEAVLRAACDQAGVRPADVRFVELHGT GTPAGDPVEAEALGAVYGTGRPANEPLLVGSVKTNIGHLEGAAGIAGFVKAALCLHERALPA SLNFETPNPAIPLERLRLKVQTAHAALQPGTGGGPLLAGVSAFGMGGTNCHVVLEETPGGRQ PAETGQADACLFSASPMLLLSARSEQALRAQAARLREHLEDSGADPLDIAYSLATTRTRFEH RAAVPCGDPDRLSSALAALAAGQTPRGVRIGSTDADGRLALLFTGQGAQHPGMGQELYTTDP HFAAALDEVCEELQRCGTQNLREVMFTPDQPDLLDRTEYTQPALFALQTALYRTLTARGTQA HLVLGHSVGEITAAHIAGVLDLPDAARLITARAHVMGQLPHGGAMLSVQAAEHDLDQLAHTH GVEIAAVNGPTHCVLSGPRTALEETAQHLREQNVRHTWLKVSHAFHSALMDPMLGAFRDTLN TLNYQPPTIPLISNLTGQIADPNHLCTPDYWIDHARHTVRFADAVQTAHHQGTTTYLEIGPH PTLTTLLHHTLDNPTTIPTLHRERPEPETLTQAIAAVGVRTDGIDWAVLCGASRPRRVELPT YAFQRRTHWAPGLTPNHAPADRPAAEPQRAMAVGPVSREALVRLVGETTASVLGLDGPDEVA LDRPFTSQGLDSMTAVELAGLLGTAAGVALDPTLVYELPTPRAVADHLAKTLLGESAADADQ EVNGRTGEAEAKAGDPIAVIGIGCRFPGGVATPDDLWELVASGTDAISTFPTDRGWDLDGLY DPDPSTPGKSYVRHGGFLHDAAQFDAEFFGISPREATAMDPQQRLLLETSWEALERAGVVPE SLRGGRTGVFVGTTAPEYGPRLHEGTDGYEGFLLTGTTASVASGRIAYALGTRGPALTVDTA CSSSLVALHLAVQSLRRGECDLALAGGTTVMSGPGMFVEFSRQRGLAPDGRCKAFSADADGT AWAEGVGMLLVERLSDAERLGHRVLAVVRGTAVNQDGASNGLTAPSGPAQQQVIRDALSDAG LSADDIDAVEAHGTGTALGDPIEAGALLATYGHPKRQTPVWLGSLKSNIGHTQAAAGIAGII KMVQALRHDTLPRTLHADHPSSKVDWDAGPLQLLTDARPWPADPDRPRRAGISAFGVSGTNA HVVLEEPPELIKGQKAKGKSENDLERPLHILTLSTKTEKALEELVSRYQNHWETYPELAISD VCYTANTGRAQFNHRLAVIASGSEELTQKLRQHTAGEEVVGVFSGKVPNSGSESKVAFLFTG QGSQYLNMGRQLYETQPTFRQALDTCDHILRPYLDNPLLEILYPQDAQKSNDSPLDQTGYTQ PALFSIEYALLKLWESWGIKPNVVMGHSVGEYVAATVAGVFSLEDGLKLIAARGRLMQGLPA GGEMVSVMASESKVLETLKAMSLEDKVAIAAINGPESIVISGEAEAIRAMATHLESVGIKTK QLQVSHAFHSPLMEPMLAEFEAVANQITYHQPRIPIISNVTGTKADKSIATAQYWVNHVRQP VRFAQGMATLHQQGYETFLEIGAKPILLGMGKQCLSPDVGVWLPSLRHGVDEWQQILSSLGQ LYVQGAKVDWSGFDRDYSREKVVLPTYPFQRERYWVETSINQQQVVCSGEPNLQGTPEGTST TIVKLLSQGNTKELAEKVEKTSDLPPEQLKLLPDLLASLSQQHQQELARLTTKKWFYKVQWI SQAIKPQRNKSNNQVCHWLILTDSKGLGKSLATHLQQLGNECSVVYQADNYQNYEPGIYHIN PSHPQEFEQVYQTIFENGKLPLQKVIHLWSLDTASEQDLTTETLEQAQLWGCGSTLHLLQTL VKNPNSTPPKLWMITRGTQPVLSPTEKLTVATSPLWGLGRTIASEHPQLWGGLVDLDPQGSE DEVEVLLQQIIDSQKEDHLAVRNRKIYVARLLKHIPQESQPLSLRSDATYLITGGLGALGLK TAAWMAEKGARNLVLISRRQPSEQAQQTIQSLEELGTQVKVLSADISVESDVANILEQIQTS LPPLLGVIHAAGVLDDGLLQQTNWERFTKVMAPKVNGTWNLHKLTQHLSLDFFVCFSSMSSL LGSPGQGNYAAANAFMDAVVHYRREMGLPGLSINWGGWSEGGMATRLASQHQNRMQTAGISL ISPEQGIQVLEELVRTQSTAQVGVLPVDWSVLAKQFSSANPSSLLLELLQQETSSEKTDERI LEKLQAAPITERQDILKNYIQLVVAKTLGINPSKISTDDNFVELGMDSLMGMEVVNKLSGDL DFIIYPREFYERPTIDSLTQYLSAELSEDNLATQPSPTSLEIFATKSSPSGNSARPASVSSR LPGIIFILSSPRSGSTLLRVMLAGHSSLFSPPELHLLPFNTMKERQEQLNLSYLGEGLQKTF MEVKNLDATASQALIKDLESQNLSIQQVYGMLQENIAPRLLVDKSPTYAMEPTILERGEALF ANSKYIYLVRHPYSVIESFVRMRMQKLVGLGEENPYRVAEQVWAKSNQNILNFLSQLEPERQ HQIRYEDLVKKPQQVLSQLCDFLNVPFEPELLQPYQGDRMTGGVHQKSLSISDPNFLKHNTI DESLADKWKTIQLPYPLKSETQRIASQLSYELPNLVTTPTNQQPQVSTTPSTEQPIMEEKFL EFGGNQICLCSWGSPEHPVVLCIHGILEQGLAWQEVALPLAAQGYRVVAPDLFGHGRSSHLE MVTSYSSLTFLAQIDRVIQELPDQPLLLVGHSMGAMLATAIASVRPKKIKELILVELPLPAE ESKKESAVNQLTTCLDYLSSTPQHPIFPDVATAASRLRQAIPSLSEEFSYILAQRITQPNQG GVRWSWDAIIRTRSILGLNNLPGGRSQYLEMLKSIQVPTTLVYGDSSKLNRPEDLQQQKMTM TQAKRVFLSGGHNLHIDAAAALASLILTS

The amino acid sequence of a PKS capable of producing styrene has the following amino acid sequence (SEQ ID NO:7):

MTKEYTRPQSAPLTEGDLLTLIVAHLAERLRMDARFIDVHEPFSRHGLDSRGAVDLVVDLRT ALGRPLSPVVVWQHPTPDALARHLAGGADAREGQARADSAYERPGAPNEPIAIVGMACRFPG APDVDSYWRLLSGGVDAVTEVPAGRWDMDAFYDRDPRSLGDVSTLRGGFIDDVDRFDAMFFG ISPREAVSMDPQQRLMLELAWEALEDAGIVAERLKESLTGVFFGCIWDDYVTLIHQRGRGAI AQHTVTGNHRSIIANRVSYTLDLRGPSMTVDSACSSALVTIHMACESLRSGESTLALAGGVN LNIAPESTIGVHKFGGLSPDGRCFTFDARANGYVRGEGGGVVVLKRLSSAIADGDPIICVIR GSAVNNDGASNGLTGPNPLAQEAVLRTAYERAGVNPADVQYVELHGTGTQLGDPVEASALGA VLGKRRPAERPLLVGSAKTNVGHLEGAAGIVGLLKAALCLKHKQLAPNLNFETPNPHIPFAE LNLKVQGALGPWPDMDRPLVCGVSSFGLGGTNAHVVLSEWASLEAELHPLAAESPEALREEV QRRLLTMTSLVGRAPLSFLCGRSAAQRSAKEHRLAVTARSFEELKQRLLGFLEHEKHVSVSA GRVDLGAAPKVVFVFAGQGAQWFGMGRALLQREPVFRTTIEQCSSFIQQNLGWSLLDELMTD RESSRLDEIDVSLPAIISIEIALAAQWRAWGVEPAFVVGHSTGEIAAAHVAGVLSIEDAMRT ICAYGRIIRKLRGKGGMGLVALSWEDAGKELTGYEGRLFRAIEHSADSTVLAGEPDALDALL QALERKNVFCRRVAMDVAPHCPQVDCLRDELFDALREVRPNKAQIPIVSEVTGTALDGERFD ASHWVRNFGDPALFSTAIDHLLQEGFDIFLELTPHPLALPAIESNLRRSGRRGVVLPSLRRN EDERGVMLDTLGVLYVRGAPVRWDNVYPAAFESMPLPSTAGGGKPLPPMPLLISARTDAALA AQAARLRAHLDSHLDLELVDVAYSLAATRTHFERRAVVVARDRAGILDGLDALAHGGSAALL GRSAAHGKLAILFTGQGSQRPTMGRALYDAFPVFRGALDAAAAHLDRDLDRPLRDVLFAPDG SEQAARLDQTAFTQPALFALEVALFELLQSFGLKPALLLGHSIGELVAAHVAGVLSLQDACT LVAARAKLMQALPQGGAMVTLQASEQEARDLLQAAEGRVSLAAVNGHLSTVVAGDEDAVLKI ARQVEALGRKATRLRVSHAFHSPHMDGMLDDFRRVAQGLTFHPARIPIISNVTGARATDQEL ASPETWVRHVRDTVRFLDGVRTLHAEGARAFLELGPHPVLSALAQDALGHDEGPSPCAFLPT LRKGRDDAEAFTAALGALHAAGLTPDWNAFFAPFAPCKVPLPTYTFQRERFWLDASTAHAAS ATPAAALEGRFWQAVESGDIDTLSSELHVDGDEQRAALALVLPTLSSFRHKRQEQSTVDAWR YRVTWKPLTTAATPADLAGTWLLVVPSALGDDALLATLTEALTRRGARVLALRVSDIHIGRS ALVEHLREALAETAPLRGVLSLLALDEHRLADRSALPAGLALSLALVQGLDDLAIEAPLWLF TRGAVSIGHSDPITHPTQAMIWGLGRVVGLEHPERWGGLVDVSAGVDESAVGRLLPALAQRH DEDQLALRPAGLYARRIVRAPLGDAPPAREFRPRGTILITGGTGALGAHVARWLARQGAEHL ILISRRGAEAPGASELHAELNALGVRTTLAACDVADRSALQALLDSIPSDCPLTAVFHTAGA RDDGLIGDMTPERIERVLAPKLDSALHLHELTKNSALDAFVLYASLSGVLGNPGQANYAAAN AFLDALAEHRRSLGLTATSVAWGGWGGGGMATERVAAQLQQRGLLQMAPSLALAALAQALQQ DETTITVADIDWSRFAPAFSVARQRPLLRDLPEAQRALQASEGASSEHGPATGLLDELRSRS ESEQLDLLATLVRGETATVLGHAEASHVDPDKGFMDLGLDSLMTVELRRRLQKATGVKLPPT LAFDHPSPHRVAFFLRDSLSEDNLATQPSPTSLEIFATKSSPSGNSARPASVSSRLPGIIFI LSSPRSGSTLLRVMLAGHSSLFSPPELHLLPFNTMKERQEQLNLSYLGEGLQKTFMEVKNLD ATASQALIKDLESQNLSIQQVYGMLQENIAPRLLVDKSPTYAMEPTILERGEALFANSKYIY LVRHPYSVIESFVRMRMQKLVGLGEENPYRVAEQVWAKSNQNILNFLSQLEPERQHQIRYED LVKKPQQVLSQLCDFLNVPFEPELLQPYQGDRMTGGVHQKSLSISDPNFLKHNTIDESLADK WKTIQLPYPLKSETQRIASQLSYELPNLVTTPTNQQPQVSTTPSTEQPIMEEKFLEFGGNQI CLCSWGSPEHPVVLCIHGILEQGLAWQEVALPLAAQGYRVVAPDLFGHGRSSHLEMVTSYSS LTFLAQIDRVIQELPDQPLLLVGHSMGAMLATAIASVRPKKIKELILVELPLPAEESKKESA VNQLTTCLDYLSSTPQHPIFPDVATAASRLRQAIPSLSEEFSYILAQRITQPNQGGVRWSWD AIIRTRSILGLNNLPGGRSQYLEMLKSIQVPTTLVYGDSSKLNRPEDLQQQKMTMTQAKRVF LSGGHNLHIDAAAALASLILTS

The amino acid sequence of a PKS (pentene ORF1) capable of producing pentene has the following amino acid sequence (SEQ ID NO:8):

MRAPYGNRQVNRRFLREFRAKRPHCVSPLHFLAEFSESRQTTGSAGVTAPIDRPGVSMAPKS GAQRSSDIAVVGMSCRLPGAPGIDEFWHLLTTGGSAIERRADGTWRGSLDGAADFDAAFFDM TPRQAAAADPQQRLMLELGWTALENAGIVPGSLAGTDTGVFVGIAADDYAALLHRSATPVSG HTATGLSRGMAANRLSYLLGLGGPSLAVDSAQSSSLVAVHLACESLRRGESDLAIVGGVSLI LAEDSTAGMELMGALSPDGRCHTFDARANGYVRGEGGACVVLKPLERALADGDRVHCVVRGS AVNNDGGGSTLTTPHREAQAAVLRAAYERAGVGPDQVSYVELHGTGTPVGDPVEAAALGAVL GTAHGRNAPLSVGSVKTNVGHLEAAAGLVGFVKAALCVREGVVPPSLNHATPNPAIPMDRLN LRVPTRLEPWPHPDDRATGRLRLAGVSSFGMGGTNAHVVVEEAPLPEAGEPVGAGVPLAVVP VVVSGRSAGAVAELASRLNESVRSDRLVDVGLSSVVSRSVFEHRSVVLAGDSAELSAGLDAL AADGVSPVLVSGVASVGGGRSVFVFPGAGVKWAGMALGLWAESAVFAESMARCEAAFAGLVE WRLADVLGDGAALEREDVVQPASFAVMVSLAALWRSLGVVPDAVVGHSQGEIAAAVVAGGLS LEDGARVVVLRARVAEEVLSGGGIASVRLSRAEVEERLAGGGGGLSVAVVNAPSSTVVAGEL GDLDRFVAACEAEGVRARRLEFGYASHSRFVEPVRERLLEGLADVRPVRGRIPFYSTVEAAE FDTAGLDAEYWFGNLRRPVRFQETVERLLADGFRVFVECGAHPVLTGAVQETAETAGREICS VGSLRRDEGGLRRFLTSAAEAFVQGVEVSWPVLFDGTGARTVDLPTYPFQRRHHWAPDGSAS AAPTRDIRPDETAAVPADTMDLAGQLRADVASLPTTEQIARLLDQVRDGVATVLGLDARDEV RAEATFKELGVESLTGVELKNHLRARTGLHVPTSLIYDCPTPLAAAHYLRDELLGRPAEQAV VPAGIPVDEPIAIVGMGCRLPGGVSSPEGLWDLVASGVDAVSPFPTDRGWDVGGLFDPEPGV PGRSYVREGGFLHEAGEFDAGFFGISPREALAMDPQQRLLLETSWEALERAGIDPHTLRGSR TGVYAGVMAQEYGPRLHEGADGYEGYLLTGSSSSVASGRISYVLGLEGPAVTVDTACSSSLV ALHLAVRALRSGECDLALAGGATVMAEPGMFVEFSRQRGLSAHGRCKAYSDSADGTGWAEGA GVLLVERLSDAVRHGRRVLAVVRGSAVNQDGASNGLTAPNGRSQSRLIRQALADARLGVADV DVVEGHGTGTRLGDPIEAQALLATYGQRDAGRPLRLGSLKSNVGHTQAAAGVAGVIKMVMAM RHGVLPKTLHVDEPTAEVDWSAGAVSLLREQEAWPRGERVRRAGVSSFGVSGTNAHVILEQP PGVPSQSAGPGSGSVVDVPVVPWMVSGKTPEALSAQATALMTYLDERPDVSSLDVGYSLALT RSALDERAVVLGSDRETLLCGVKALSAGHEASGLVTGSVGAGGRIGFVFSGQGGQWLGMGRG LYRAFPVFAAAFDEACAELDAHLGQEIGVREVVSGSDAQLLDRTLWAQSGLFALQVGLLKLL DSWGVRPSVVLGHSVGELAAAFAAGVVSLSGAARLVAGRARLMQALPSGGGMLAVPAGEELL WSLLADQGDRVGIAAVNAAGSVVLSGDRDVLDDLAGRLDGQGIRSRWLRVSHAFHSYRMDPM LAEFAELARTVDYRRCEVPIVSTLTGDLDDAGRMSGPDYWVRQVREPVRFADGVQALVEHDV ATVVELGPDGALSALIQECVAASDHAGRLSAVPAMRRNQDEAQKVMTALAHVHVRGGAVDWR SFFAGTGAKQIELPTYAFQRQRYWLVPSDSGDVTGAGLAGAEHPLLGAVVPVAGGDEVLLTG RISVRTHPWLAEHRVLGEVIVAGTALLEIALHAGERLGCERVEELTLEAPLVLPERGAIQVQ LRVGAPENSGRRPMALYSRPEGAAEHDWTRHATGRLAPGRGEAAGDLADWPAPGALPVDLDE FYRDLAELGLEYGPIFQGLKAAWRQGDEVYAEAALPGTEDSGFGVHPALLDAALHATAVRDM DDARLPFQWEGVSLHAKAAPALRVRVVPAGDDAKSLLVCDGTGRPVISVDRLVLRSAAARRT GARRQAHQARLYRLSWPTVQLPTSAQPPSCVLLGTSEVSADIQVYPDLRSLTAALDAGAEPP GVVIAPTPPGGGRTADVRETTRHALDLVQGWLSDQRLNESRLLLVTQGAVAVEPGEPVTDLA QAALWGLLRSTQTEHPDRFVLVDVPEPAQLLPALPGVLACGEPQLALRRGGAHAPRLAGLGS DDVLPVPDGTGWRLEATRPGSLDGLALVDEPTATAPLGDGEVRIAMRAAGVNFRDALIALGM YPGVASLGSEGAGVVVETGPGVTGLAPGDRVMGMIPKAFGPLAVADHRMVTRIPAGWSFARA ASVPIVFLTAYYALVDLAGLRPGESLLVHSAAGGVGMAAIQLARHLGAEVYATASEDKWQAV ELSREHLASSRTCDFEQQFLGATGGRGVDVVLNSLAGEFADASLRMLPRGGRFLELGKTDVR DPVEVADAHPGVSYQAFDTVEAGPQRIGEMLHELVELFEGRVLEPLPVTAWDVRQAPEALRH LSQARHVGKLVLTMPPVWDAAGTVLVTGGTGALGAEVARHLVIERGVRNLVLVSRRGPAASG AAELVAQLTAYGAEVSLQACDVADRETLAKVLASIPDEHPLTAVVHAAGVLDDGVSESLTVE RLDQVLRPKVDGARNLLELIDPDVALVLFSSVSGVLGSGGQGNYAAANSFLDALAQQRQSRG LPTRSLAWGPWAEHGMASTLREAEQDRLARSGLLPISTEEGLSQFDAACGGAHTVVAPVRFS RLSDGNAIKFSVLQGLVGPHRVNKAATADDAESLRKRLGRLPDAEQHRILLDLVRMHVAAVL GFAGSQEITADGTFKVLGFDSLTVVELRNRINGATGLRLPATLVFNYPTPDALAAHLVTALS ADRLAGTFEELDRWAANLPTLARDEATRAQITTRLQAILQSLADVSGGTGGGSVPDRLRSAT DDELFQLLDNDLELP

The amino acid sequence of a PKS (pentene ORF2) capable of producing pentene has the following amino acid sequence (SEQ ID NO:9):

MSNEEKLREYLRRALVDLHQARERLHEAESGEREPIAIVAMGCRYPGGVQDPEGLWKLVASG GDAIGEFPADRGWHLDELYDPDPDQPGTCYTRHGGFLHDAGEFDAGFFDISPREALAMDPQQ RLLLEISWETVESAGMDPRSLRGSRTGVFAGLMYEGYDTGAHRAGEGVEGYLGTGNAGSVAS GRVAYAFGFEGPAVTVDTACSSSLVALHLACQSLRQGECDLALAGGVTVMSTPERFVEFSRQ RGLAPDGRCKSFAAAADGTGWGEGAGLVLLERLSDARRNGHRVLAVVRGSAVNQDGASNGLT APNGLAQERVIQQVLTSAGLSASDVDAVEAHGTGTRLGDPIEAQALIAAYGQDRDRDRPLWL GSVKSNIGHTQAAAGVAGVIKMVMAMRHGELPRTLHVDEPNSHVDWSAGAVRLLTENIRWPG TGTRRAGVSSFGVSGTNAHVIVGDYAQQKSPLAPPATQDRPWHLLTLSAKNAQALNALQKSY GDYLAQHPSVDPRDLCLSANTGRSPLKERRFFVFKQVADLQQTLNQDFLAQPRLSSPAKIAF LFTGQGSQYYGMGQQLYQTSPVFRQVLDECDRLWQTYSPEAPALTDLLYGNHNPDLVHETVY TQPLLFAVEYAIAQLWLSWGVTPDFCMGHSVGEYVAACLAGVFSLADGMKLITARGKLMHAL PSNGSMAAVFADKTVIKPYLSEHLTVGAENGSHLVLSGKTPCLEASIHKLQSQGIKTKPLKV SHAFHSPLMAPMLAEFREIAEQITFHPPRIPLISNVTGGQIEAEIAQADYWVKHVSQPVKFV QSIQTLAQAGVNVYLEIGVKPVLLSMGRHCLAEQEAVWLPSLRPHSEPWPEILTSLGKLYEQ GLNIDWQTVEAGDRRRKLILPTYPFQRQRYWFNQGSWQTVETESVNPGPDDLNDWLYQVAWT PLDTLPPAPEPSAKLWLILGDRHDHQPIEAQFKNAQRVYLGQSNHFPTNAPWEVSADALDNL FTHVGSQNLAGILYLCPPGEDPEDLDEIQKQTSGFALQLIQTLYQQKIAVPCWFVTHQSQRV LETDAVTGFAQGGLWGLAQAIALEHPELWGGIIDVDDSLPNFAQICQQRQVQQLAVRHQKLY GAQLKKQPSLPQKNLQIQPQQTYLVTGGLGAIGRKIAQWLAAAGAEKVILVSRRAPAADQQT LPTNAVVYPCDLADAAQVAKLFQTYPHIKGIFHAAGTLADGLLQQQTWQKFQTVAAAKMKGT WHLHRHSQKLDLDFFVLFSSVAGVLGSPGQGNYAAANRGMAAIAQYRQAQGLPALAIHWGPW AEGGMANSLSNQNLAWLPPPQGLTILEKVLGAQGEMGVFKPDWQNLAKQFPEFAKTHYFAAV IPSAEAVPPTASIFDKLINLEASQRADYLLDYLRRSVAQILKLEIEQIQSHDSLLDLGMDSL MIMEAIASLKQDLQLMLYPREIYERPRLDVLTAYLAAEFTKAHDSEAATAAAAIPSQSLSVK TKKQWQKPDHKNPNPIAFILSSPRSGSTLLRVMLAGHPGLYSPPELHLLPFETMGDRHQELG LSHLGEGLQRALMDLENLTPEASQAKVNQWVKANTPIADIYAYLQRQAEQRLLIDKSPSYGS DRHILDHSEILFDQAKYIHLVRHPYAVIESFTRLRMDKLLGAEQQNPYALAESIWRTSNRNI LDLGRTVGADRYLQVIYEDLVRDPRKVLTNICDFLGVDFDEALLNPYSGDRLTDGLHQQSMG VGDPNFLQHKTIDPALADKWRSITLPAALQLDTIQLAETFAYDLPQEPQLTPQTQSLPSMVE RFVTVRGLETCLCEWGDRHQPLVLLLHGILEQGASWQLIAPQLAAQGYWVVAPDLRGHGKSA HAQSYSMLDFLADVDALAKQLGDRPFTLVGHSMGSIIGAMYAGIRQTQVEKLILVETIVPND IDDAETGNHLTTHLDYLAAPPQHPIFPSLEVAARRLRQATPQLPKDLSAFLTQRSTKSVEKG VQWRWDAFLRTRAGIEFNGISRRRYLALLKDIQAPITLIYGDQSEFNRPADLQAIQAALPQA QRLTVAGGHNLHFENPQAIAQIVYQQLQTPVPKTQ

Nucleic Acids Encoding the PKS

The present invention provides recombinant nucleic acids that encode the PKSs of the invention. The recombinant nucleic acids include double-stranded and single:stranded DNAs and RNA derived therefrom. The recombinant nucleic acids of the invention include those that encode an open reading frame (ORF) of a PKS of the present invention. The recombinant nucleic acids of the invention also include, in a variety of embodiments, promoter sequences for transcribing the ORF in a suitable host cell. The recombinant nucleic acids of the invention include, in some embodiments, sequences sufficient for having the recombinant nucleic acid stably replicate in a host cell, such as sequences that provide a replicon capable of stable maintenance in a host cell or sequences that direct homologous recombination of the nucleic acid into a chromosome of the host cell. In some embodiments, the nucleic acid is a plasmid, including but not limited to plasmids containing an origin of replication. The present invention also provides vectors, such as expression vectors, comprising another recombinant nucleic acid of the present invention. The present invention provides host cell comprising any of the recombinant nucleic acids and/or capable of expressing a PKS of the present invention. In some embodiments, the host cell, when cultured under suitable conditions, is capable of producing an α-olefin of the invention.

It will be apparent to one of skill in the art that a variety of recombinant vectors can be utilized in the practice of the invention. As used herein, “vector” refers to polynucleotide elements that are used to introduce recombinant nucleic acid into cells for either expression or replication (or both). Selection and use of such vectors generally is routine in the art. An “expression vector” is a recombinant nucleic acid capable of expressing (producing proteins encoded by) DNA coding sequences (and corresponding mRNA) that are operatively linked with regulatory sequences, such as promoters. Thus, an expression vector refers to a recombinant DNA or RNA construct, such as a plasmid, a phage, a recombinant virus, or other vector that, upon introduction into an appropriate host cell that when cultured under appropriate conditions, results in expression of the DNA coding sequence. Appropriate expression vector elements suitable for use in accordance with the present invention are well known to those of skill in the art and include those that are replicable in eukaryotic cells and/or prokaryotic cells and those that remain episomal as well as those that integrate into the host cell genome.

The vectors of the invention include those chosen to contain control sequences operably linked to the resulting coding sequences in a manner that expression of the coding sequences may be effected in an appropriate host. Suitable control sequences include those that function in eukaryotic and prokaryotic host cells. If the cloning vectors employed to obtain PKS genes lack control sequences for expression operably linked to the PKS-encoding nucleotide sequences, the nucleotide sequences are inserted into appropriate expression vectors. This can be done individually, or using a pool of isolated encoding nucleotide sequences, which can be inserted into “host” vectors, the resulting vectors transformed or transfected into host cells, and the resulting cells plated out into individual colonies. Suitable control sequences for single cell cultures of various types of organisms are well known in the art. Control systems for expression in yeast are widely available and are routinely used. Control elements include promoters, optionally containing operator sequences, and other elements depending on the nature of the host, such as ribosome binding sites. Particularly useful promoters for prokaryotic hosts include those from PKS gene clusters that result in the production of polyketides as secondary metabolites, including those from Type I or aromatic (Type II) PKS gene clusters. Examples are act promoters, tcm promoters, spiramycin promoters, and the like. However, other bacterial promoters, such as those derived from the genes encoding sugar metabolizing enzymes, such as those that metabolize galactose, lactose (lac) and maltose, are also useful. Additional examples include promoters derived from the genes encoding biosynthetic enzymes such as those that encode the enzymes for tryptophan (trp) biosynthesis, the β-lactamase (bla) gene promoter, bacteriophage lambda PL promoter, and the T5 promoter. In addition, synthetic promoters, such as the tac promoter (U.S. Pat. No. 4,551,433; incorporated herein by reference), can be used to construct an expression vector of the invention.

As noted, particularly useful control sequences are those which themselves, or with suitable regulatory systems, activate expression during transition from growth to stationary phase in the vegetative mycelium. Illustrative control sequences, vectors, and host cells of these types include the modified Streptomyces coelicolor CH999 and vectors described in PCT publication No. WO 96/40968 and similar strains of Streptomyces lividans. See U.S. Pat. Nos. 5,672,491; 5,830,750; 5,843,718; and 6,177,262, each of which is hereby incorporated by reference. Other regulatory sequences may also be desirable; these include those that allow for regulation of expression of the PKS sequences relative to the growth of the host cell. Regulatory sequences are known to those of skill in the art, and examples include those which cause the expression of a gene to be turned on or off in response to a chemical or physical stimulus, including the presence of a regulatory compound. Other types of regulatory elements may also be present in the vector, for example, enhancer sequences.

Selectable markers can also be included in the recombinant expression vectors of the invention. A variety of markers are known that are useful in selecting for transformed cell lines; these generally are any gene whose expression confers a selectable phenotype on transformed cells when the cells are grown in an appropriate selective medium. Such markers include, for example, genes that confer antibiotic resistance or sensitivity to a host cell.

The various PKS nucleotide sequences, or a mixture of such sequences, can be cloned into one or more recombinant vectors as individual cassettes, with separate control elements or under the control of a single promoter. The PKS encoding subunits or components can include flanking restriction sites to allow for the easy deletion and insertion of other PKS encoding subunits. The design of such restriction sites is known to those of skill in the art and can be accomplished using the techniques described in the scientific literature, such as site-directed mutagenesis and PCR. Methods for introducing the recombinant vectors of the present invention into suitable hosts are known to those of skill in the art and include the use of CaCl₂ or other agents, such as other divalent cations, lipofection, DMSO, protoplast transformation, conjugation, and electroporation.

Host Cells Comprising the PKS

The present invention provides host cells comprising the recombinant nucleic acid and/or PKS of the present invention. In many embodiments, the host cell, when cultured, is capable of producing an α-olefin. The host cell can be a eukaryotic or a prokaryotic cell. Suitable eukaryotic cells include yeast cells, such as from the genus Saccharomyces, Candida, or Schizosaccharomyces. A suitable species from the genus Saccharomyces is Saccharomyces cerevisiae. A suitable species from the genus Schizosaccharomyces is Schizosaccharomyces pombe. Suitable prokaryotic cells include, but are not limited to, the gram negative Escherichia coli and the gram positive Streptomyces species, such as S. coelicolor and S. lividans.

The PKSs of the invention can be in a host cell, and can isolated and purified. The PKS can synthesize the α-olefin in vivo (in a host cell) or in vitro (in a cell extract or where all necessary chemical components or starting materials are provided). The present invention provides methods of producing the α-olefin using any of these in vivo or in vitro means.

In some embodiments of the invention, the host cell comprises a PKS which produces butadiene comprising a loading module comprising an acrylyl-ACP starter, such as a DEBS proprionyl-CoA specific loading domain which is modified to accept acrylyl-CoA, and one or more nucleic acids encoding and capable of expressing biosynthetic enzymes for synthesizing acrylyl-CoA from propionate (see FIG. 8). An example of a set of such enzymes is propionyl-CoA ligase (synthetase) (EC 6.2.1.17) and acyl-CoA dehydrogenase (mammalian) (EC 1.3.99.3), and functional variants thereof. In some embodiments, the host cell comprises a nucleic acid encoding and capable of expressing an enzyme, or functional variant thereof, capable of converting propionate into propionyl-CoA, and an enzyme, or functional variant thereof, capable of converting propionyl-CoA into acrylyl-CoA. An enzyme capable of converting propionate into propionyl-CoA is the propionyl-CoA ligase encoded by the prpE gene of Salmonella typhimurium. An enzyme capable of converting propionyl-CoA into acrylyl-CoA is the mammalian acyl-CoA dehydrogenase. A host cell comprising this system is provided with propionate, such as by exogenously feeding propionate to the host cell, or produces propionate endogenously.

The amino acid sequence of the propionyl-CoA ligase encoded by the prpE gene in Salmonella typhimurium (GenBank accession no. NP_(—)459366) comprises:

(SEQ ID NO: 13) 1 msfsefyqrs inepeafwae qarridwrqp ftqtldhsrp pfarwfcggt tnlchnavdr 61 wrdkqpeala liayssetde ertftfsqlh devnivaaml lslgvqrgdr vlvympmiae 121 aqitllacar igaihsvvfg gfashsvaar iddarpaliv sadagarggk ilpykklldd 181 aiaqaqhqpk hvllvdrgla kmawvdgrdl dfatlrqqhl gasvpvawle snetscilyt 241 sgttgkpkgv qrdvggyava latsmdtifg gkaggvffca sdigwvvghs yivyapllag 301 mativyeglp typdcgvwwk ivekyqvnrm fsaptairvl kkfptaqirn hdlsslealy 361 lagepldept aswvtetlgv pvidnywqte sgwpimalar alddrpsrlg spgvpmygyn 421 vqllnevtge pcginekgml viegplppgc iqtiwgddar fvktywslfn rqvyatfdwg 481 irdaegyyfi lgrtddvini aghrlgtrei eesissypnv aevavvgikd alkgqvavaf 541 vipkqsdtla dreaardeen aimalvdnqi ghfgrpahvw fvsqlpktrs gkmlrrtiqa 601 egrdpgdl ttiddpaslq qirqaiee

The amino acid sequence of the acyl-CoA dehydrogenase of Mus musculus (GenBank accession no. Q07417) comprises:

(SEQ ID NO: 14) 1 maaallarar gplrralgvr dwrrlhtvyq svelpethqm lrqtcrdfae kelvpiaaql 61 drehlfptaq vkkmgelgll amdvpeelsg aglgylaysi aleeisraca stgvimsvnn 121 slylgpilkf gsaqqkqqwi tpftngdkig cfalsepgng sdagaastta reegdswvin 181 gtkawitnsw easatvvfas tdrsrqnkgi saflvpmptp gltlgkkedk lgirasstan 241 lifedcripk enllgepgmg fkiamqtldm grigiasqal giaqasldca vkyaenrnaf 301 gapltklqni qfkladmala lesarlltwr aamlkdnkkp ftkesamrkl aaseaatais 361 aiqilgsm gyvtempaer yyrdaritei yegtseiqrl viaghllrsy rs

In some embodiments, the host cell of the invention comprises a PKS which produces butadiene and comprises a loading module comprising an acrylyl-ACP starter, such as a DEBS proprionyl-CoA specific loading domain which is modified to accept acrylyl-CoA, and one or more nucleic acids encoding and capable of expressing biosynthetic enzymes for synthesizing acrylyl-CoA from pyruvate (see FIG. 9). An example of a set of such enzymes is lactate dehydrogenase (EC 6.2.1.17), lactate CoA transferase (EC 2.8.3.1), propionyl-CoA ligase (synthetase) (EC 6.2.1.17), and lactoyl-CoA dehydratase (EC 4.2.164), or functional variants thereof. In some embodiments, the host cell comprises one or more nucleic acids encoding and capable of expressing these four enzymes. A host cell comprising this system is provided with propionate and a suitable organic molecule that the host cell can directly or indirectly convert into a pyruvate, and these compounds are either exogenously fed to or produced by the host cell. For example, if the host cell is E. coli, a suitable organic molecule is glucose.

The amino acid sequence of the lactate dehydrogenase encoded by the IdhA gene of E. coli (GenBank accession no. CAQ31881) comprises:

(SEQ ID NO: 15) 1 taktangcea vcifvnddgs rpvleelkkh gvkyialrca gfnnvdldaa kelglkvvry 61 paydpeavae haigmmmtln rrihrayqrt rdanfslegl tgftmygkta gvigtgkigv 121 amlrilkgfg mrllafdpyp saaalelgve yvdlptlfse sdvislhcpl tpenyhllne 181 aafdqmkngv mivntsrgal idsqaaieal knqkigslgm dvyenerdlf fedksndviq 241 ddvfrrlsac hnvlftghqa fltaealtsi sqttlqnlsn lekgetcpne lv

The amino acid sequence of the lactate CoA transferase encoded by the pct gene of Clostridium proponicum (GenBank accession no. CAB77207) comprises:

(SEQ ID NO: 16) 1 mrkvpiitad eaaklikdgd tvttsgfvgn aipealdrav ekrfletgep knityvycgs 61 qgnrdgrgae hfahegllkr yiaghwatvp algkmamenk meaynvsqga lchlfrdias 121 hkpgvftkvg igtfidprng ggkvnditke divelveikg qeylfypafp ihvalirgty 181 adesgnitfe kevaplegts vcqavknsgg ivvvqvervv kagtldprhv kvpgiyvdyv 241 vvadpedhqq sldceydpal sgehrrpevv geplplsakk vigrrgaiel ekdvavnlgv 301 gapeyvasva deegivdfmt ltaesgaigg vpaggvrfga synadalidq gyqfdyydgg 361 gldlcylgla ecdekgninv srfgpriagc ggfinitqnt pkvffcgtft agglkvkied 421 gkviivqegk qkkflkaveq itfngdvala nkqqvtyite rcvfllkedg lhlseiapgi 481 qtqildvm dfapiidrda ngqiklmdaa lfaeglmglk emks

The amino acid sequence of the lactoyl-CoA dehydratase encoded by the pct gene of Clostridium proponicum (GenBank accession no. CAB77206) comprises:

(SEQ ID NO: 17) 1 efkiaivddd laqesrqiry dvldgeggpl yrmakawqqm ygcslatdtk kgrgrmlink 61 tiqtgadaiv vammkfcdpe ewdypvmyre feekgvkslm ievdqevssf eqiktrlqsf 121 veml

In some embodiments, the host cell of the invention comprises a PKS which produces butadiene and comprises a loading module comprising an acrylyl-ACP starter, such as a DEBS proprionyl-CoA specific loading domain which is modified to accept acrylyl-CoA, and one or more nucleic acids encoding and capable of expressing biosynthetic enzymes for synthesizing acrylyl-CoA from acetyl CoA (see FIG. 10). An example of a set of such enzymes is acetyl-CoA carboxylase (EC 6.4.1.2), malonyl-CoA reductase (EC 1.2.1.75), 3-hydroxypropionate:CoA ligase, and 3-hydroxypropionyl-CoA hydratase (EC 4.2.1.17), or functional variants thereof. In some embodiments, the host cell comprises one or more nucleic acids encoding and capable of expressing the four enzymes described. A host cell comprising this system can be engineered to produce increased titers of acetyl-CoA.

In some embodiments, the host cell of the invention comprises a PKS which produces butadiene and comprises a loading module comprising an acrylyl-ACP starter, such as a DEBS proprionyl-CoA specific loading domain which is modified to accept acrylyl-CoA, and one or more nucleic acids encoding and capable of expressing biosynthetic enzymes for synthesizing acrylyl-CoA from propionate (see FIG. 15). An example of a set of such enzymes is propionyl-CoA ligase (synthetase) (EC 6.2.1.17), lactoyl-CoA dehydratase (EC 4.2.164), lactate dehydrogenase (EC 6.2.1.17), lactate CoA transferase (EC 2.8.3.1), or functional variants thereof. A host cell comprising this system is provided with propionate, either by exogenous feeding or by endogenous production.

In some embodiments, the host cell of the invention comprises a PKS which produces 3-methyl-2,4-pentadienoic acid and comprises the modules shown in FIG. 12 including a loading module comprising an acrylyl-ACP starter, such as a DEBS proprionyl-CoA specific loading domain which is modified to accept acrylyl-CoA, and one or more nucleic acids encoding and capable of expressing biosynthetic enzymes for synthesizing acrylyl-CoA (see FIG. 12). There are several methods for enabling a host cell to synthesize acrylyl-CoA described above. 3-methyl-2,4-pentadienoic acid can be enzymatically, catalytically, or pyrolytically converted to isoprene.

Methods of Producing α-olefins Using the PKS

The present invention provides a method of producing an α-olefin comprising: providing a host cell of the present invention, and culturing said host cell in a suitable culture medium such that the α-olefin is produced. The method can further comprise isolating said α-olefin from the host cell and/or the culture medium. The method can further comprise polymerizing the α-olefin to itself and/or any other suitable organic molecule(s), including but not limited to other compounds comprising a C—C double bond. A variety of methods for heterologous expression of PKS genes and host cells suitable for expression of these genes and production of polyketides are described, for example, in U.S. Pat. Nos. 5,843,718; 5,830,750 and 6,262,340; WO 01/31035, WO 01/27306, and WO 02/068613; and U.S. Patent Application Pub. Nos. 20020192767 and 20020045220; each of which is incorporated herein by reference.

The present invention provides for a composition comprising an α-olefin isolated from a host cell from which the α-olefin is produced, and trace residues and/or contaminants of the host cell. Such trace residues and/or contaminants include cellular material produced by the lysis of the host cell. The present invention also provides α-olefins in substantially pure form.

Certain α-olefins produced by the PKSs of the present invention can be used as fuels. In some embodiments of the invention, an α-olefin produced in accordance with the invention can be used as a “green” jet fuel. The α-olefin can be catalytically oligomerized, including but not limited to dimerized, and optionally purified. The resulting products can be dimerized again to yield a mixture of branched molecules that are then catalytically hydrogenated. For example, 1-butene produced by a PKS of the present invention can be catalytically dimerized and purified. The resulting octene products can be dimerized again to yield a mixture of branched C16 molecules that are then catalytically hydrogenated. Oligomers of butene have been validated by the US Navy as both jet and diesel fuel replacements (Harvey, 2011. Journal of Chemical Technology and Biotechnology 86(1): 2-9.). Additional benefit may come from making branched, or aromatic, α-olefins using the avermectin (or other) loading modules, as described herein.

Thus, among others, the present invention has one or more of the following advantages: (1) it reduces the dependence on oil for producing certain chemicals, and (2) it serves as a means of capture and sequestration of carbon from the atmosphere.

The invention having been described, the following examples are offered to illustrate and not limit the subject invention.

EXAMPLES

Constructs can be conveniently designed at the amino acid level and then, back translation and DNA synthesis, such as that offered commercially by service providers such as DNA 2.0, can be conducted to yield the desired nucleic acid, which may be optimized for expression in a particular host cell type. Subsequent plasmid assembly can be conducted using standard molecular biology techniques.

Example 1 Production of 1-Hexene Using a PKS-Based Enzyme System

In one embodiment of the invention, PKS modules from three different organisms were used to construct a tri-ketide pathway designed for the production of 1-hexene. In this embodiment, the 1-hexene synthase consists of two ORFs. HexORF1 combines EryA1 loading module+KS1 and AT-ACP from IdmO, HexORF2 utilizes the KS domain from IdmP and AT-TE domains from CurM. In another embodiment of this invention the loop I region of the indanomycin sourced ACP in HexORF1, SSSAGIDPGRAFQDMGI, is swapped with ASAERVPADQAFAELGV, the segment of ACP directly following EryA1. Both of these designs were back translated using software designed to optimize expression in E. coli. The genes are synthesized and ligated into two pairs of compatible, E. coli expression vectors that are subsequently transformed into E. coli BAP-1. The amino acid sequences for HexORF1, HexORF1′, and HexORF2 are provided as SEQ ID NOs: 2-4, respectively.

Experiments have been performed demonstrating E. coli BAP-1 utilizing exogenously added propionate. In both examples of 1-hexene production, overnight cultures of a pBbA7C-HexORF1′ (or pBbA7C-HexORF1)+pBbS7k-HexORF2 cotransformed strain were grown from a single colony and used to inoculate (1% v/v) three 50-mL cultures of LB medium supplemented with 0.5% glucose and 10% glycerol in 250 mL screw cap (unsealed) flask. Cultures were grown to an OD600 of 1.0 to 1.2, induced with 50 uM IPTG and grown at (30° C.) for an additional 3 hours. Then 100 mM propionate was supplemented to the culture and a Teflon septum was used to seal the cap. The cultures were then grown at 20° C. for 24 hours after which 1-butene was detectable in the headspace of the culture using solid phase micro extraction followed by GC-MS.

Example 2 Production of Butadiene Using a PKS-Based Enzyme System

An example of a PKS system for producing butadiene is shown in FIGS. 6 and 7. The system built to produce 1-butene, described below, was fed acrylate to produce butadiene. Otherwise, all experimental details are as described as that for 1-butene production, above. While the limits of detection were inadequate to determine productivity in this instance, the invention provides several routes to increasing butadiene productivity, including: adding an acrylate specific CoA ligase to the host strain, adding an acrylate importer to the host strain, and/or utilizing a host strain less sensitive to acrylate toxicity.

Example 3 Production of 1-Butene Using a PKS-Based Enzyme System

An illustrative PKS system for producing 1-butene was constructed using the AT-TE PKS domains from CurM and the loading module for propionyl-CoA+KS1 from EryA1. For in vivo 1-butene production, overnight cultures of E. coli BAP1 carrying pBbS7k-Butene (PKS protein sequence provided as SEQ ID NO:5) were grown from a single colony and used to inoculate (1% v/v) three 50-mL cultures of LB medium supplemented with 0.5% glucose and 10% glycerol in 250 mL screw cap (unsealed) flask. Cultures were grown to an OD600 of 1.0 to 1.2, induced with 50 uM IPTG and grown at (30° C.) for an additional 3 hours. Then 100 mM propionate was supplemented to the culture and a Teflon septum was used to seal the cap. The cultures were then grown at 20° C. for 24 hours after which 1-butene was detectable in the headspace of the culture using solid phase micro extraction followed by GC-MS.

Example 4 Production of Isoprene Using a PKS-Based Enzyme System

An example of a PKS system for producing isoprene is shown in FIG. 12.

Example 5 Production of (E)-penta-1,3-diene Using a PKS-Based Enzyme System

An example of a PKS system for producing (E)-penta-1,3-diene is shown in FIG. 13.

Example 6 Production of Propene (Propylene) Using a PKS-Based Enzyme System

An illustrative propene synthase of the invention is a single enzyme consisting of the loading module+KS1 from the niddamycin PKS (Kakavas, 1997) fused to AT-TE domains from CurM (Chang, 2004; Gu, 2009) (the amino acid sequence for this construct is provided as SEQ ID NO:6). For in vivo propene production, overnight cultures of E. coli BAP1 carrying pBbS7k-propene were grown from a single colony and used to inoculate (1% v/v) three 50-mL cultures of LB medium supplemented with 0.5% glucose and 10% glycerol in 250 mL screw cap (unsealed) flask. Cultures were grown to an OD600 of 1.0 to 1.2, induced with 50 uM IPTG and grown at (30° C.) for an additional 3 hours. Then a Teflon septum was used to seal the cap. The cultures were then grown at 20° C. for 24 hours after which propene was detectable in the headspace of the culture using solid phase micro extraction followed by GC-MS.

Example 7 Production of Styrene Using a PKS-Based Enzyme System

An illustrative styrene synthase of the invention was constructed by fusing the ST and TE domains from CurM onto the loading and first extension modules from the soraphen PKS (Schupp, 1995; Wilkinson, 2001). The amino acid sequence for this construct is provided as SEQ ID NO:7. For styrene biosynthesis in the system illustrated, a pool of benzoyl-CoA is provided. To facilitate production of this essential precursor, the styrene synthase construct was coexpressed with an E. coli codon optimized gene encoding benzoate-CoA ligase, badA, from Rhodopseudomonas palustris (Egland, et al., J. Bacteriol. 1995 November; 177(22):6545-51.) and fed exogenous benzoate. For in vivo styrene production, overnight cultures of E. coli BAP1 carrying pBbS7k-SS1(SS1 encodes SEQ ID NO:7) were grown from a single colony and used to inoculate (1% v/v) three 50-mL cultures of LB medium supplemented with 0.5% glucose and 10% glycerol in 250 mL screw cap (unsealed) flask. Cultures were grown to an OD600 of 1.0 to 1.2, induced with 50 uM IPTG and grown at (30° C.) for an additional 3 hours. Then 100 mM benzoic acid was supplemented to the culture and a Teflon septum was used to seal the cap. The cultures were then grown at 20° C. for 24 hours after which styrene was detectable in the headspace of the culture using solid phase micro extraction followed by GC-MS.

Example 8 Production of Pentene Using a PKS-Based Enzyme System

An illustrative pentene synthase of the invention was designed as two ORFs. The first ORF is built using the chalcomycin PKS loading module+KS 1 fused to spinosad AT-ACP PKS module two. The second ORF is the KS from spinosad M3 fused to the olefination module (Ols) from Synechococcus sp. PCC7002 (Mendez-Perez, et al., Appl Environ Microbiol. 2011 June; 77(12):4264-7). The amino acid sequences for these chimeric proteins are provided as SEQ ID NO:8 and 9.

While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto. 

1. A non-naturally occurring polyketide synthase (PKS), or functional variant thereof, capable of synthesizing an α-olefin.
 2. The PKS of claim 1, wherein the α-olefin is not a compound synthesized by a naturally occurring PKS.
 3. The PKS of claim 1, wherein the PKS is a hybrid PKS comprising modules, domains, and/or portions thereof, or functional variant thereof, from two or more PKSs.
 4. The PKS of claim 3, wherein the PKS comprises a terminal module comprising ST, and TE, or functional variant thereof, of Lyngbya majuscula CurM.
 5. The PKS of claim 4, wherein the PKS comprises a terminal module comprising KR, ACP, ST, and TE, or functional variant thereof, of Lyngbya majuscula CurM.
 6. The PKS of claim 5, wherein the PKS comprises a terminal module comprising AT, KR, ACP, ST, and TE, or functional variant thereof, of Lyngbya majuscula CurM.
 7. The PKS of claim 3, wherein the PKS comprises at least one terminal module comprising a ST and a TE, or functional variant thereof, described in Tables 2-4.
 8. The PKS of claim 3, wherein the PKS comprises a loading module which incorporates acrylyl-CoA.
 9. The PKS of claim 3, wherein the PKS comprises the loading module is a DEBS proprionyl-CoA specific loading domain modified to accept acrylyl-CoA.
 10. The PKS of claim 9, wherein the PKS comprises a module in which a terminal carbon is incorporated as a methyl group which is later oxidized.
 11. The PKS of claim 1, wherein the α-olefin has the following chemical structure:

wherein each R₁ is independently —H or —CH₃, each R₂ is independently —H or —OH, n is an integer from 1 to 10, αβ is (1) a single bond or (2) a double bond, with the proviso that when an αβ is a double bond then the corresponding R₂ is H.
 12. The PKS of claim 11, wherein the α-olefin is 1-hexene, 1-decene, or (E)-deca-1,5-diene.
 13. The PKS of claim 1, wherein the α-olefin is an aromatic α-olefin having the following chemical structure:

wherein R₃ is —H, —OH, —NH₃, or —NO₂.
 14. The PKS of claim 1, wherein the α-olefin has the following chemical structure:

wherein R is one of the following structures


15. A recombinant nucleic acid encoding the polyketide synthase (PKS) of claim
 1. 16. A replicon comprising the recombinant nucleic acid 14, wherein the replicon is capable of stable maintenance in a host cell.
 17. The replicon of claim 16, wherein the replicon is a plasmid or vector.
 18. The replicon of claim 17, wherein the vector is an expression vector.
 19. A host cell comprising the recombinant nucleic acid of claim
 15. 20. A host cell comprising the replicon of claim
 16. 21. The host cell of claim 19, wherein the host cell when cultured produces the α-olefin.
 22. The host cell of claim 21, wherein the host cell comprises a PKS which produces butadiene comprising a loading module comprising an acrylyl-ACP starter, and further comprises one or more nucleic acids encoding propionyl-CoA ligase (synthetase) (EC 6.2.1.17) and acyl-CoA dehydrogenase (mammalian) (EC 1.3.99.3), or functional variants thereof, wherein when cultured and optionally provided with propionate the PKS is capable of synthesizing acrylyl-CoA and producing butadiene.
 23. The host cell of claim 21, wherein the host cell comprises a PKS which produces butadiene comprising a loading module comprising an acrylyl-ACP starter, and further comprises one or more nucleic acids encoding lactate dehydrogenase (EC 6.2.1.17), lactate CoA transferase (EC 2.8.3.1), propionyl-CoA ligase (synthetase) (EC 6.2.1.17), and lactoyl-CoA dehydratase (EC 4.2.164), or functional variants thereof, wherein when cultured and optionally provided with propionate and glucose the PKS is capable of synthesizing acrylyl-CoA and producing butadiene.
 24. The host cell of claim 21, wherein the host cell comprises a PKS which produces butadiene comprising a loading module comprising an acrylyl-ACP starter, and further comprises one or more nucleic acids encoding acetyl-CoA carboxylase (EC 6.4.1.2), malonyl-CoA reductase (EC 1.2.1.-), 3-hydroxypropionate:CoA ligase, and 3-hydroxypropionyl-CoA hydratase (EC 4.2.1.17), or functional variants thereof, wherein when cultured the PKS is capable of synthesizing acrylyl-CoA and producing butadiene
 25. The host cell of claim 21, wherein the host cell comprises a PKS which produces butadiene comprising a loading module comprising an acrylyl-ACP starter, and further comprises one or more nucleic acids encoding propionyl-CoA ligase (synthetase) (EC 6.2.1.17), the AccA/PccB gene products and lactoyl-CoA dehydratase (EC 4.2.164), and lactate dehydrogenase (EC 6.2.1.17), lactate CoA transferase (EC 2.8.3.1), propionyl-CoA ligase (synthetase) (EC 6.2.1.17), and lactoyl-CoA dehydratase (EC 4.2.164), or acyl-CoA dehydrogenase, or functional variants thereof, wherein when cultured and optionally provided with propionate the PKS is capable of synthesizing acrylyl-CoA and producing butadiene.
 26. A method of producing an α-olefin, comprising: providing a host cell of claim 21, and culturing said host cell in a suitable culture medium such that the α-olefin is produced.
 27. The method of claim 26, further comprising isolating the isolating the α-olefin.
 28. The method of claim 27, further comprising polymerizing the α-olefin to produce a polymer.
 29. The method of claim 26, wherein the α-olefin is a polyolefin.
 30. The method of claim 29, wherein the polyolefin is butadiene, isoprene, or (E)-deca-1,5-diene.
 31. A composition comprising an α-olefin isolated from the host cell of claim 21, and trace residues and/or contaminants of the host cell.
 32. The composition of claim 31, wherein the α-olefin is polyolefin.
 33. The composition of claim 32, wherein the polyolefin is butadiene, isoprene, or (E)-deca-1,5-diene. 